Preheat griddle pan on the grill or a stovetop frying pan
Form the ground beef into equally-sided round balls.
Do not smash burger balls or try to make them into a burger shape.
Place the beef balls onto a lightly oiled griddle or in a frying pan.
Using the back of a grill spatula, flatten each burger ball into a thin patty.
Let them cook, without flipping or touching until the bottoms are brown and the edges start to look crispy.
Flip the burgers and let them continue to cook until the bottoms brown.
While the burgers are grilling, toast the tops and bottoms of each bun.
Top the burgers with cheese.
To assemble the burger, smear mustard on the bottom bun.
Add the shredded lettuce on top of the mustard.
Next comes the tomato slices.
Place two cheeseburgers on the tomato slice and add the top bun.