You are here: Home » Recipes » In-N-Out Burger Copycat In-N-Out Burger Copycat Recipe by Leigh Anne Wilkes Yield 4-8 servings Fast-food from home is infinitely better—here's a handcrafted recipe from In-N-Out. Leigh Anne Wilkes PrintEmail Ingredients 2 pounds ground chuck (60%)4 Hamburger buns (if making doubles; 8 buns if making singles)2 tablespoons vegetable oil2 large onions1/4 cup mayonnaise2 tablespoons ketchup1 tablespoon sweet pickle relish 1/2 teaspoon white vinegar1 cup shredded iceburg lettuce 4-8 slices tomato8 slices American cheese Pickles Salt Black pepper Instructions Heat oil in pan and add onions. Cover onions and cook over medium heat for 30 minutes or until onions begin to turn golden brown and caramelize. Watch them so they don’t burn. Remove lid and cook for 5 more minutes; add 1/2 cup water. Allow water to cook out. Set onions aside; they can be made several days ahead of time and refrigerated. Mix together mayo, ketchup, relish and vinegar in a bowl and set aside. Heat griddle and lightly brush with vegetable oil. Toast buns on griddle, split side down. After buns are toasted golden brown spread each bottom bun with 1 tablespoon of mayo mixture. Top with tomato and lettuce. Form meat into 8 patties about 4 inches wide and 1/2 inch thick. Season both sides of hamburger patties with salt and pepper and cook on griddle for 3-5 minutes. Spread 1 1/2 teaspoons of mustard on the top, uncooked side of each patty and flip. Top patty with cheese and allow to cook until desired doneness. Add hamburger to bun and top with caramelized onion. This recipe originally appeared as In-N-Out Burger Copycat Recipe on yourhomebasedmom.com.