Step 1

In a bowl, toss the onion slices wit the salt and let them sit.

Step 2

Divide the meat into four patties, handling the meat gently as you form the patties.

Step 3

Heat a large frying pan or flat top over medium-high heat.

Step 4

Add 1 tablespoon of the canola oil.

Step 5

Place one of the patties in the hot oil and immediately smash it flat with a spatula or bacon press, holding it for 30 seconds.

Step 6

Sprinkle the pepper on the patty.

Step 7

Cover the patty with 1/4 of the onions and allow the beef to cook until a brown jacket forms on the bottom, about 2 minutes.

Step 8

Carefully flip the burger and press it down again. You may need to use your other hand or another spatula to hold the onions on the patty as you flip.

Step 9

Add the salt and the pepper to the patty, being somewhat conservative because of the thinness of the patty.

Step 10

Lay 1 slice of the cheese on the patty and cook until the cheese is melted and the beef is at your level of desired doneness, about 2-4 minutes.

Step 11

In a separate pan, melt the butter.

Step 12

Toast the buns in the melted butter until crisp and golden, about 2-4 minutes.

Step 13

Place the top of one of the burger buns on the cheese and use the spatula to lift the burger from the pan, pressing down on the burger bun with your hand to ensure the burger stays in place as you move it.

Step 14

Place the burger on the bottom bun.

Step 15

Repeat this process with each of the remaining burgers and the remaining ingredients, using more of the extra canola oil as needed before cooking each patty.

Step 16

Serve with the pickles and the mustard.