1 large onion, peeled, halved and thinly sliced

salt and pepper

1/2-3/4 lb ground beef

1 tablespoon butter, plus additional butter for buns

1 tablespoon vegetable oil

2 slices American cheese

2 hamburger buns, toasted or grilled

Combine the onion slices and 1 teaspoon of salt in a bowl and toss to combine. Transfer the onions to a colander and let sit for 30 minutes, tossing occasionally. Transfer the onions to a clean dish towel, gather the edges together and squeeze out as much liquid as you can from the onions. Do this over the sink or a large bowl since the onions will have quite a bit of liquid in them.

Set heat to medium high on griddle or stove top. Drizzle griddle or skillet with butter and olive oil. Divide the onions into 2 separate rounds and place on hot griddle or skillet. Form the beef into 2 loosely packed patties. Place the patties on top of the onion rounds and push down with a spatula so the onion adheres to the beef. The patties should measure 4 inches in diameter. Season the beef generously with salt and pepper.

Cook for 6-8 minutes, until the onions turn a deep golden brown and begin to crisp around the edges. Flip the burgers, then increase the heat to high and cook until well browned on the second side, about 2 minutes.

Add 1 or 2 slices of cheese to each burger and allow to melt.  Butter cut sides of buns and grill, buttered side down on griddle or skillet or toast. Place onion burgers on buns to serve.  Add preferred condiments if desired.