Grilled Onion Wrapped Burger

Slice a large onion into four thick, 1/2-inch rounds to serve as the 'buns'.

Heat olive oil in a large skillet over medium-low heat. Add the onion slices in a single layer.

Drizzle a little more olive oil over the top of the onions and season with garlic salt.

Cook the onions slowly, flipping occasionally, until they are soft and deeply caramelized. This may take 15-20 minutes.

While the onions are cooking, combine the ground beef, Worcestershire sauce, and burger seasoning in a bowl. Mix gently to combine.

Divide the beef mixture into four equal portions and roll them into balls.

Once the onions are well-caramelized, drizzle balsamic vinegar over them and toss to coat. Cook for another minute, then remove from the pan and set aside.

Place the beef balls into the same hot skillet.

Using a burger press or a sturdy spatula, smash each ball into a thin patty.

Squeeze a layer of yellow mustard onto the top (uncooked) side of each patty.

Cook for 2-3 minutes, then flip the patties so the mustard side sears on the pan.

Immediately top each patty with a slice of American cheese. Stack two patties together to create a double patty.

Cover the pan with a lid for about a minute to allow the steam to melt the cheese.

To assemble, place one caramelized onion slice on a plate, top with a double-stack of cheesy patties, add burger sauce and chopped banana peppers, and finish with a second onion slice.