Copycat In-N-Out Double-Double Animal-Style Burger

Ingredients

• 0.5 cups mayonnaise
• 1.5 tablespoons ketchup
• 1 tablespoon pickle relish
• 1 teaspoon sugar
• 0.75 teaspoons white vinegar
• 1 tablespoon butter
• 1 tablespoon canola oil
• 3 cups yellow onions
• 0.75 teaspoons salt , divided
• 4 tablespoons water
• 1 lb ground chuck
• 1 teaspoon canola oil
• 0.5 teaspoons black pepper
• 3 tablespoons mustard
• 8 slices merican cheese
• 4 hamburgers buns , toasted
• 16 dills pickle chips
• 4 slices tomato
• 2 leaves iceberg lettuce , torn

Instructions

1. 1

   Stir together mayonnaise, ketchup, relish, sugar, andvinegar in a small bowl for the sauce.

2. 2

   Heat butter and 1 tablespoon oil in a nonstick skilletover medium heat. Add onions and season with ¼ teaspoon salt. Cook, stirring occasionally, until onions are tender and golden brown, about 20 minutes. When skillet starts to become dry, add 1 tablespoon water. Continue cooking, stirring often, adding more water as needed, 1 tablespoon at a time, until onions are very soft, deeply browned, and jammy, 10 to 15 minutes more. You may not need to use all the water. Remove from heat.

3. 3

   Shape beef into 8 patties, about 3/8-inch-thick and 4inches in diameter. Sprinkle with pepper and remaining 1/2 teaspoon salt.

4. 4

   Heat 1 teaspoon oil in a large cast-iron skillet overmedium-high heat. Working in batches as needed, add patties to skillet. Spread 2 teaspoons mustard over top of each patty. Cook until browned, about 2 minutes per side. Top patties with cheese and onions. Cook, covered, about 30 seconds, until cheese is melted. An instant-read thermometer inserted into the center should read at least 160 degrees F (70 degrees C). Layer patties to create 4 stacks.

5. 5

   Spread sauce onto bun bottoms. Fill each bun with 4 pickles, a tomato slice, lettuce, and 1 patty stack.