Squashing the ground beef and onions together into a hot skillet makes a great burger with crispy edges and caramelized onion flavor.
1 lb. ground beef
2 medium Vidalia or Spanish onions
4 Tb. canola oil
Salt to taste
American cheese (optional)
6 Hamburger buns, toasted
Dill pickle slices
Divide the ground beef into 6 equal balls. Thinly slice the onions using a mandoline or slice them using a sharp knife. Divide the onions into 6 equal portions.
Working in two batches, heat 2 Tbsp. of the oil in a 12-inch cast-iron skillet over medium high heat. Add 3 of the beef balls and using the back of a spatula, press down on them until they are thin. Cook for 1 minutes. Top each patty with a portion of the onions, then season with salt. Press the onions into the meat and cook for about 1 minute more.
Flip the onion-topped patties and flatten them with the spatula. Place a cheese slice, if using on each patty and let the cheese melt while the onions and the meat brown. Top the bottom half of each bun with the onions and cheese-topped patties, add the top bun, and serve with dill pickles.