01 - In a mixing bowl, combine ground beef, salt, black pepper, Worcestershire sauce, and grated onion if using. Form into four equal patties, slightly larger than the buns.
02 - Heat a grill or skillet over medium-high heat until hot.
03 - Grill the patties for 3 to 4 minutes per side for medium doneness. During the last minute, place a slice of cheddar on each patty and cover to melt the cheese.
04 - Butter the cut sides of the buns and toast them on the grill or skillet until golden brown.
05 - Spread mayonnaise and ketchup on the bottom bun if desired. Layer with lettuce, tomato slice, beef patty with melted cheese, and red onion. Cap with the top bun.
06 - Serve immediately alongside preferred accompaniments.