Corned beef: add 2 of your 4 cups of water to a medium-sized pot. Add kosher salt, granulated sugar, cloves, allspice berries, pink curing salt, coriander seeds, mustard seeds, black peppercorns and bay leaves to the water and bring to a boil. This is your brine. 

Allow the brine to cool slightly and add the last 2 cups of water. 

Add your 3 to 4-pound brisket to a container that you can store in the refrigerator for the next five days. Cover the brisket with your brine. Add more water if needed to keep the brisket fully submerged in the brine. 

Store the container with the brisket for the next five days. At least once a day, flip the brisket and stir up the brine. 

After five days remove the brisket and discard the brine. Rinse off the brisket in cold water until it is clean of all brine, seeds and peppercorns. 

Preheat oven to 300 F (148 C).

Add the brisket to an oven-safe pot or dutch oven that will hold it. Add as much water as needed to fully cover the brisket.

Over medium-high heat, bring the pot containing the brisket and water to a boil. Once it has come to a boil, remove from the heat, cover the pot and add it to the preheated oven. If you do not have an oven-safe lid for this pot, you can wrap the top in two layers of aluminum foil. 

Cook for 3 to 4 hours until the corned beef is very tender when pierced with a knife.

Allow corned beef to cool for at least an hour before slicing. Slicing is best if the meat is cool, so resting overnight in the refrigerator would be best. Meat slices best when it is firmer and cooler.

Slice as thin as possible against the grain so that the resulting slices are very tender. 

Quick sauerkraut: (recipe adapted from Michael Voltaggio) slice your cabbage and onion very thin and add to a microwave-safe bowl. Add the other sauerkraut ingredients and toss everything together to combine well. 

Cover the bowl with plastic wrap and microwave for 5 minutes. Allow the bowl to cool; with the plastic wrap still covering it for 15 minutes. 

Store the sauerkraut in a jar or sealed container in the refrigerator. 

Sandwich assembly: heat a large pan or griddle over medium-low heat. Wait five minutes for the pan to be hot.

Spread butter on one side of one piece of rye bread and then place that butter side down on the hot pan/griddle. Add Russian dressing on top of the bread and then add a slice of Swiss cheese.

Add several slices of corned beef on top of the cheese.

On top of the corned beef, add a generous amount of sauerkraut, and top the kraut with the second slice of Swiss cheese (if using). Spread Russian dressing on the second slice of bread and lay the bread on top of the Swiss cheese with the Russian dressing facing down on top of the cheese. 

Spread a little more butter on top of the Top slice of bread and cook the whole thing for 2 or 3 minutes and then flip. Cook for another 2 or 3 minutes and then flip again. At this point, you want to cook the sandwich, flipping back and forth until the bread looks nice and brown but not burned, so you might have to flip it another 2 or 3 times. 

Once the bread is browned to your liking, remove it from heat and serve the Reuben sandwich.