Ingredients
Filling
4 burger patties (or 1/2 pound ground beef)
1 tablespoon oil
1 sweet onion diced
1/2 teaspoon salt or to taste
1/2 teaspoon freshly ground black pepper
8 slices American cheese or cheddar cheese

For the Bread
4 hero rolls sliced 3/4 through
2 tablespoons mayonnaise or to taste
2 tablespoons ketchup or to taste

Topping
2 to matoes sliced
3 cups iceberg lettuce shredded

Instructions
Prepare the Bread
Slice hero rolls 3/4 of the way through with a serrated knife.
Toast the buns on a large skillet or grill pan. Set aside.

Make the Filling
Add oil to a large non-stick skillet over medium high heat. Add diced onions and sauté until caramelized. Transfer to a bowl and set it aside.Season the patties with salt and pepper. Increase the heat to high, and add burger patties in the same skillet. Cook for about 4 minutes or until the bottom is nicely browned. Flip the burger and cook for 1 minute. Use 2 steel spatulas to chop the burger into small pieces. Stirring constantly.m Add the cooked onions and keep chopping and stirring. Divide into 4 even portions and top each with 2 slices of cheese and turn off the heat so the cheese can melt properly.

Assemble the Sandwich
Spread a thin layer of mayo on the hero roll. Drizzle ketchup on top. Use a steel spatula and carefully transfer the filling into each roll. Add sliced tomatoes and shredded iceberg lettuce on top of the filling. Season with more salt and pepper if preferred. (Optional) Wrap each roll with aluminum foil. Cut in half, serve warm and enjoy!