Place the ground beef in a bowl. Add salt, black pepper, garlic powder, and Worcestershire sauce. Gently mix with your hands until just combined — avoid overworking. Divide into 4 equal portions and form each into a 3/4-inch thick patty slightly wider than the bun. Make a shallow dimple in the center of each patty with your thumb to prevent doming.

Preheat and cook

Preheat a heavy skillet or cast-iron pan over medium-high heat for 3–4 minutes until very hot. Add the vegetable oil and swirl to coat. Place the patties in the skillet (work in two batches if needed) and cook undisturbed for 3 minutes. Flip once and cook 2 minutes on the second side for medium doneness. During the last 45 seconds of cooking, place a cheddar slice on each patty and cover the pan with a lid to melt the cheese.

Finish patties

Remove the patties to a plate and tent loosely with foil to rest for 3 minutes while you prepare buns and toppings.

Buns & Toppings

Prep vegetables and condiments

While the patties rest, slice the tomato into 4 even slices. Thinly slice the red onion into rings to equal about 1/4 cup. Mix mayonnaise and mustard together in a small bowl to make a quick burger spread.

Toast buns

Heat a clean skillet over medium heat. Spread softened butter evenly on the cut sides of the brioche buns. Place buns butter-side down in the skillet and toast 1–2 minutes until golden brown. Remove from heat.

Assemble Cheese Willie

Spread about 1 tablespoon of the mayo-mustard mixture on the bottom half of each toasted bun. Place a lettuce leaf, then a tomato slice, then a cheesy beef patty. Top each patty with two pickle slices and some red onion. Spread remaining sauce on the top bun and place it over the stack. Serve immediately.