Just a heads up: I don’t have any experience eating tonkatsu sandwiches in Japan and I’m not a chef or a knowledge expert on Japanese cuisine, so if you’re looking for a super authentic version of tonkatsu, you might have to check elsewhere. My goal with this blog post is to write about a tasty sandwich that I’ve been inspired to make and share how you can make one too.
What is tonkatsu?
Tonkatsu itself is not a sandwich. It’s a Japanese dish or entrée that has transitioned into something that is often sandwiched between slices of bread. According to Wikipedia, tonkatsu originated way back in the 1800s as thinly pounded, crispy fried meat that was possibly inspired by European-style breaded meat cutlets. After making tonkatsu a few times, it is believable to me that it could have been inspired by something like German schnitzel.
In Japanese, the word “ton” translates to pork or pig and the word “katsu” is a shortened version of a Japanese word that translates to “cutlet.” So, we’re working with a pork cutlet or a thin piece of pork. These pork cutlets are pounded thin and fried, typically crusted in crispy breadcrumbs. Those fried pieces of pork are served as an entrée without bread, and they can also be served in sandwich form with thinly sliced cabbage and a sweet and tangy barbecue-like sauce called katsu sauce.
A typical tonkatsu-style sandwich—or sando as they are known—will be served on very soft white bread slices with the crust removed. This bread is usually of a variety of shokupan or Japanese milk bread. If you want a deeper dive into katsu sandwiches, you should check out this Sandwich Tribunal katsu sando post. Or read on for more of my tonkatsu experiences.
Note: this blog post contains even more than our normal amount of bread/dough content, so use the navigation below if you’re not a baker and you want to jump over that and skip all the pictures and words about bread.
Japanese milk bread (shokupan)
Japanese milk bread—also known as shokupan—is a big deal in the bread-baking world these days. This style of bread is known for being super soft, and squishy white bread.
The Japanese word shokupan translates to “eating bread.”
This style of bread is so soft that it doesn’t work for all types of sandwiches. Some meats and cheeses need a little more stability for stacking onto slices of bread. Toasting shokupan can help if your sandwich needs a bit more structure than squishy white bread.
The main tactic involved in Japanese milk bread is a method called tangzhong, which is a hot side blending of liquid (usually milk or water) and flour. Basically, you cook flour with the liquid until they become very much like paste or a roux.
The word tangzhong is of Chinese origin and it roughly translates to “water roux.”
The gist of the science behind tangzhong is that you’re exposing a small portion of the flour to hot water or milk which encourages the starches in the flour to absorb more of the liquid. With this method, you’re able to raise the moisture level in your bread recipe which results in softer bread that will last longer and rise higher.
A dough that starts with a tangzhong paste will rise taller in part because the liquid in the dough creates extra steam in the oven. Steam is one of the factors that helps baked bread to rise.
A moist bread will take longer to dry out and become stale. Basically, you’re pre-loading your dough with moisture that helps the dough expand in the oven and extends the shelf-life of your slices.
The tangzhong process provides all of this added benefit to your loaves and it only adds about 5 extra minutes to your dough prep time.
There’s a great Introduction to tangzhong blog post over at King Arthur Baking if you’d like to learn more about the process and a deeper dive into the science.
Milk bread dough shaping
Now we get down to business.
At this point I have made this recipe quite a few times, using three different ways of shaping the loaf and two different pans. If you research this style of bread, you will see that many bakers shape balls or cylinders of dough and place them in a pan. If you don’t care about the appearance of the bread, it’s easiest just to shape all the dough and bake it in a loaf pan like any other loaf of bread you might have baked, but it’s not much harder to make it a two-hump loaf.
I believe most professional bakers baking shokupan would be rolling logs of dough, but I found it just as easy and just as pretty to form the dough into two equally sized balls and roll and shape those balls to be as smooth as possible. Place those in a lightly greased pan and the dough will rise to fill in the corners and rise to the top. If you’re trying to become a professional baker, maybe you shouldn’t listen to me, but for home bakers, I can confirm this works and is easy to shape.
Dough pan volume math
Last week when I was getting all the words and photos polished for this blog post, I saw an email newsletter come in from Andrew Janjigian @ Wordloaf. If you aren’t already subscribed and you like baking, you should sign up. In this edition of his newsletter, Janjigian wrote about dough volume in baking pans. There’s a particular graphic that they shared that uses some calculations to determine the number of grams you should be putting into your dough pans.
The magic of this graphic is that you could use it to convert any loaf bread recipe you find as long as the recipe uses ingredients listed in grams and specifies which pan the recipe is meant to be baked in.
Inspired by the dough volume content in this newsletter, I decided that I would test the same Japanese milk bread recipe in two different sizes of loaf pan. I wanted to see how well the same volume of bread dough by grams would work in the two differently sized pans.
Two pan shokupan showdown
Since I’ve baked this recipe in both a regular 4×8-inch standard loaf pan—that you might already have if you bake banana bread—and a 4×9-inch small Pullman pan, I figured I’d show examples of what both look like with the same exact milk bread recipe. The 4×8-inch pan is much shorter (2.6-inches tall vs 4-inches tall) which will cause the rising dough to mushroom over the top of the pan a little.
|Good Cook 8×4-inch loaf pan
|2.6″D x 4″W x 9″H
|$25 for 2 pans
|USA Pan Pullman loaf pan, small
|4″D x 4″W x 9″H
|$25 for 1 pan
These pictures are of the dough, fully proofed, after one hour of waiting for the oven to preheat.
In the next two photos, we’re looking at fully baked loaves, still in the pan. Note: the angle of the sides of each loaf pan is a bit exaggerated from the angle of the camera.
As you can see below, with the 4×8-inch standard pan, the ends seem to angle out quite a bit which means the first and last “heel” slices are a bit awkward to cut without wasting bread.
There’s also a difference in the color of the bread that’s below the lip of the pan. The Pullman pan is made from thicker alloy steel and the standard pan that I own is made from aluminum. The way these different materials conduct heat is what is causing the color differences.
Below are some photos of each loaves during the slicing process.
And here we have three slices perfect for your next club sandwich.
I personally am just fine with the mushroom effect on bread, it seems normal to me, but it’s just not as consistent. The Pullman pan produces bread that can be cut into rectangles for a big tonkatsu sandwich.
If you have a 4×8-inch standard pan this recipe works just fine. There’s a bit too much dough for that pan but if you’re ok with the mushroom aesthetic, you can use the same recipe for both styles of pan. The standard loaf pan is what I used for all the sandwiches in this blog post. But if you want to make the most standardized and tallest loaf, you’ll want the small Pullman loaf pan.
Katsu sauce is important in this sandwich because it lends a zingy, sweet barbecue-like sauce that can help to cut through the richness of a fried pork cutlet.
I wanted to try to make my own katsu sauce and since I’ve never been to Japan to eat one of these sandwiches for real, I figured I would need to try a popular Japanese brand. I ordered some Bull-Dog Tonkatsu sauce from Amazon and while I was waiting for the delivery I spotted Bachan’s Japanese Barbecue Sauce in the Asian section at my local market. So, I got the idea to do a little taste of my recipe, Bachan’s and Bull-Dog to see where the differences were.
Note: Bachan’s does not claim to be a katsu sauce, it’s just a Japanese Barbecue Sauce but I figured I’d try it next to the other two anyway since the katsu sauce I had made and the Bull-Dog were both heavily barbecue sauce-focused.
Bachan’s is way thinner than the other two in terms of consistency. I don’t think it’s trying to be a katsu sauce, but it’s still really good. Bachan’s is expensive. It would be fantastic as a marinade or even a dip for dumplings or something like gyoza.
Bull-Dog and my first attempt at this sauce were pretty close but I tweaked mine a little after this tasting. The consistency is right on, and the color is almost identical. I didn’t nail the flavor 100%, but I got it really close. At this point, I’ve had several tonkatsu sandwiches with my sauce and several using Bull-Dog, and when mixed into a sandwich with bread, cabbage, and fried pork the sauces are super close in flavor and texture. Close enough for me to call it a win.
Looks like some versions of this sandwich will just have straight up very thinly shaved cabbage and some will dress the cabbage with salt and/or lemon juice. I tried both from my experiences and you should certainly salt the cabbage. The lemon juice didn’t add much in the way of flavor, but it does add brightness to contribute to the fresh cabbage in this fried pork sandwich.
Tonkatsu pork cutlet
For these sandwiches, I bought a couple of pork tenderloins on special at our local grocery store. You need the meat to be thin, so pounding it with a kitchen mallet is probably the best technique for achieving this.
The breading station for these cutlets is typical for Panko-crusted fried foods where you start with flour, then an egg and liquid mix, and then straight into seasoned Panko breadcrumbs. The first stage of plain all-purpose flour forms a layer that blends with the egg layer to help the breadcrumbs stick really well to the meat.
Tonkatsu sandwich recipe
I made about 8 of these sandwiches over the course of a week. Most of the pork was fried in oil and a couple of pork cutlets were baked in the oven. Both recipes and quite a few sandwich photos are below.
Almost all the tonkatsu sandwich recipes that you’ll see tell you to cut the crusts off the bread and I did that on most of my sandwiches. The taste is pretty much the same either way though so if you’re making this at home, just do as you like and make yourself happy.
Here’s my tonkatsu sandwich recipe that I’ve made quite a few times at this point. There’s also an oven-baked recipe version and a bunch more photos down below.
This is a crispy, fried pork cutlet that is sandwiched between soft white bread. The sweet, salty and zippy katsu sauce brings big balance to all of the sandwich flavors.
- 4 tablespoons ketchup
- 2 tablespoons Worcestershire sauce
- 1 1⁄2 tablespoons oyster sauce
- 2 teaspoons soy sauce
- 1 teaspoon mirin
- 1 teaspoon honey
- 2 four-to-six-ounce pieces of pork tenderloin
- 1⁄2 cup all-purpose flour
- 1 large egg
- 1⁄2 cup buttermilk
- 1 teaspoon salt
- 1 teaspoon black pepper
- 1 teaspoon onion powder
- 1 teaspoon garlic powder
- 1 teaspoon paprika
- 1 cup Panko breadcrumbs
- peanut oil (enough to fill 2 inches deep in a large skillet)
- 4 slices of soft white bread
- katsu sauce (from above)
- 1⁄2 to 1 cup shaved or shredded cabbage
- pork cutlets (from above)
- mayonnaise or Dijon mustard (optional)
Katsu sauce: in a medium bowl, combine all ingredients and whisk to fully incorporate.
Store in the refrigerator for up to two weeks.
Tonkatsu preparation: Cut your pork tenderloin into a shape around the size of your bun. For me, this was around 5 ounces.
Butterfly each piece by cutting the tenderloin down the middle about two-thirds of the way through. Don't cut all the way. This will allow you to "open" the meat like a book.
Place your butterflied meat on a cutting board and cover it with a piece of plastic wrap. Using a meat mallet or something heavy like a cast iron skillet, pound the plastic wrap covered meat until each piece is about a quarter of an inch thick.
Set up a breading station with three bowls or plates.
The first bowl should have all-purpose flour in it. The second bowl will contain your egg and buttermilk. Mix to combine.
The third bowl will contain your panko breadcrumbs along with salt, pepper, onion powder, garlic powder, and paprika. Stir well.
Dunk and coat each piece of tenderloin in flour and then in the egg mixture, flipping a few times in both bowls to fully coat.
Then bread each egg-coated tenderloin and coat it in the bowl with the seasoned Panko breadcrumbs. Make sure to press the breadcrumbs into the pork to fully coat each piece.
Once each piece is fully coated, move to a plate or sheet pan to rest.
In a pot or pan over medium-high heat, add 2 inches of peanut or other vegetable oil for frying. When the oil has reached 350 F degrees you are ready to fry.
Add each tenderloin or work in batches if they don't both fit in the pan without overlapping.
Cook each tenderloin on the first side for 3 to 4 minutes. Flip and cook for an additional 3 to 4 minutes. At this point, you can check for doneness with a meat thermometer. 145 is done for pork, but some people will prefer it more than that. I personally pull mine out around 140 because it will continue to rise in temperature for a few minutes after being removed from the oil.
Transfer to a paper towel-lined plate to let some of the excess oil drip off.
Tonkatsu sandwich assembly: place two slices of bread down on a cutting board or clean surface. Add katsu sauce to both slices.
Top the katsu sauce with a big handful (or half) of the shredded cabbage. Top the cabbage with a fried pork cutlet.
Drizzle katsu sauce on top of the pork cutlet. Optionally add mayonnaise and/or Dijon mustard to the other slices of bread and use those slices to complete the sandwich.
For a traditional presentation, cut the crusts off the bread and slice the sandwich in half.
Serve and enjoy.
Oven baked tonkatsu sandwich
Here are photos of two of the oven-baked tonkatsu sandos that I made. The recipe is down below.
Oven baked tonkatsu sandwich recipe
If you want a little bit less messy cooking process in exchange for a slightly less crispy/crunchy sandwich, you can choose to bake your pork cutlet in the oven with a panko crumb crust. The flavors will still be the same. Panko baked things do bring crunch and the cleanup is less than half of the amount of work than when frying.
Make your own tonkatsu sandos
Check back next week when I’ll be blending two classics into one not-classic sandwich.