Cook bacon: you can either cook three slices in a pan until its crispy, or you can bake the bacon in the oven. I typically bake a whole bunch at a time and reheat it as needed. Here is my baked bacon recipe. Either way you cook it, make sure you reserve the bacon grease to be used in other parts of this sandwich. 

In a small or medium bowl, crack two eggs and scramble them together well with a fork or whisk. Add a small pinch of salt and any black pepper if desired. Move the bowl of eggs to the side to rest while you toast your roll. 

Add a teaspoon of bacon grease to a non-stick pan over medium heat, and when the grease is liquid and hot, place a split roll in the pan and move both pieces around to make sure they are coated in the grease. Toast the bun for 2 to 3 minutes or until the roll is just starting to get toasted and has just a tiny bit of golden brown color. 

Remove the pan from the heat and wipe it out. Place the roll on a plate or cooling rack while you cook the eggs. 

Add 2 teaspoons of bacon grease to the wiped-out pan and place it back over medium to medium-low heat. 

Pour in the eggs and using a spatula or turner, scramble them for a few minutes until some small curds start to form. Clean up any eggs at the edges of the pan, and if there's still a lot of liquid on top of your eggs, tilt the pan so that the liquid runs to the sides and starts cooking faster.  Continue cooking, tightening the edges until the top of the eggs is still moist looking, but not super wet. 

At this point you can add a slice of cheese right to the middle of the eggs. After the cheese has been added, we're going to use it as a guide for how to fold the eggs. Start lifting up and loosening the edges of the eggs near the sides of the pan. Flip all four edges over on top of the slice of cheese, forming a folded egg package around the cheese slice. 

After the eggs are formed into a folded package, add any additional cheese slices on top, and add the already cooked bacon to the pan. Turn the stove heat off and let everything sit in the pan, warming while you prepare the roll. 

Add any mayo and/or ketchup to your toasted roll. 

Build the sandwich by adding the egg and cheese package, and then top with bacon. I typically cut each slice of bacon in half so that I have 6 pieces to arrange in layers on top of the eggs. Top everything with the top of the Kaiser roll, and the sandwich is built. 

For an authentic NYC-style bacon, egg, and cheese experience, you probably should wrap the sandwich in paper or foil for just a couple of minutes before eating. This will steam all of the ingredients and ensure that everything is warm and melty. Wrapping is easy. You just need a square of paper or foil (NYC bodegas typically use both).