Copycat In-N-Out Burger

Heat oil in a skillet (use one that has a lid—you’ll need it later) over medium heat then add onions. Add onions, stir to coat the onions with the oil then put the lid on. Cook onions for 30 minutes or until onions begin to turn golden brown and caramelize. Watch them so they don’t burn. After 30 minutes, remove lid and cook for 5 more minutes. Then add 1/2 cup of water. Allow water to evaporate. Then remove the pan from the heat and set aside. Onions can be made several days ahead of time and refrigerated.

Mix together the mayo, ketchup, relish and vinegar in a bowl and set aside.

Form meat into 8 patties about 4 inches wide and 1/2 inch thick. Set them aside for a moment.

Heat a griddle to medium-high heat and lightly brush the griddle with vegetable oil. Toast the buns on the griddle, split side down. After they are toasted golden brown, remove them from the griddle and spread the bottom bun with 1 tablespoon of the mayo mixture. Set the buns on plates or a platter. Add the tomato and lettuce to the bottom bun.

Salt and pepper both sides of the hamburger patties and cook on the griddle for 3-5 minutes. Spread top of patty with 1 1/2 teaspoon of mustard and flip. Top each patty with cheese and allow to cook until done to your liking. Another 5 minutes should give you medium rare.
Add hamburger to the bun and top with caramelized onions, pickles and the top bun.