shake shack burger... 25 minutes

the goods:

shake sauce:
1/2 cup mayonnaise
1 tablespoon ketchup
1 tablespoon yellow mustard
4 slices dill pickles
1/4 teaspoon garlic powder
1/4 teaspoon paprika
pinch of cayenne

burgers:
8 ounces ground beef sirloin
8 ounces ground beef chuck
1 tablespoon vegetable oil
2 tablespoons butter, room temperature
4 potato burger buns
curly lettuce
2 vine-ripened tomatoes, sliced
1/2 teaspoon vegetable oil
4 slices American cheese

Combine mayonnaise, ketchup, mustard, pickles, garlic powder, paprika, and cayenne in a food processor, and pulse until smooth. Refrigerate until ready to use.
Gently mix together sirloin and chuck in a mixing bowl until combined. Form into 4 patties, leaving a thumb indentation in the center of each patty.
Heat oil in a cast-iron skillet over medium-high heat. Generously season patties with salt and pepper, then transfer, seasoned-side-down, to the hot skillet. Use a heavy, flat spatula to press down and lightly flatten patties. Season top-side with salt and pepper. Cook until crisp-brown crust has formed, about 3 minutes. Carefully loosen patties from skillet and flip. Top with a slice of cheese and cook until cheese has melted, about 1 to 2 minutes more.
Split open buns and lightly butter the inside of each half. Toast on a griddle or skillet until toasted. Spread buns with shake sauce on both sides. Top each bun half with a patty, then tomato, lettuce, and top bun. Serve with additional shake sauce.