Place the ground beef in a large bowl. Add kosher salt, black pepper, Worcestershire sauce, and garlic powder. Gently fold the seasonings into the meat with your hands or a spatula until evenly combined — do not overwork (about 12–15 turns).

Form patties

Divide the mixture into 2 equal portions (for 2 burgers). Lightly shape each portion into a patty about 3/4 inch thick and slightly larger than the bun. Make a shallow 1/2-inch-wide dimple in the center of each patty with your thumb to reduce puffing while cooking.

Rest

Place the patties on a plate, cover loosely, and refrigerate for 15–20 minutes to firm up (optional but helps with searing).

Cook

Heat a heavy skillet or cast-iron pan over medium-high heat and add 1 tablespoon neutral oil. When the oil is shimmering, add the patties (do not crowd). Cook for 3–4 minutes without moving to develop a crust. Flip and cook another 3 minutes for medium (adjust time for desired doneness). In the final 60–90 seconds, place a slice of cheddar on each patty and cover the pan or tent with foil to melt the cheese.

Buns & Spread

Prepare buns

While patties rest or in the last minutes of cooking, spread softened butter on cut sides of buns. Place buns butter-side down on a skillet or griddle over medium heat and toast until golden, about 1–2 minutes. Remove and keep warm.

Combine sauces

In a small bowl, mix mayonnaise, yellow mustard, and ketchup until smooth. Taste and adjust — add a pinch of salt or a dash of hot sauce if desired.

Toppings & Assembly

Prep toppings

Thinly slice red onion into rings. Wash and dry lettuce leaves. Slice tomato into 4 even slices. Have pickle slices and any optional extras (bacon, avocado) ready.

Build

Spread about 1 1/2 tablespoons of the mayo-mustard-ketchup mixture on the bottom half of each toasted bun. Place lettuce leaf on the sauce, then a cheese-topped patty, then tomato slice(s), red onion rings, and pickle slices. Add optional bacon or avocado if using. Spread a little sauce on the top bun and close the burger.

Finish

Serve immediately while hot with your choice of side (fries, salad). Provide extra condiments on the side.