In a medium bowl, whisk together the egg, mustard, Worcestershire sauce, onion powder, garlic powder, salt and pepper with a fork. Add the ground beef and mix until combined, you may need to use your hands.

Divide into 4 quarter-pound portions and shape into a thin rectangle or square (to fit your sandwich bread). Patty will be thin, handle carefully as you transport it to your grill.

Preheat greased grill (or skillet if using stove-top) to medium high heat.

Grill until slightly charred, about 2-3 minutes, then flip and cook 1-2 minutes more until cooked through. Top with cheddar cheese and cook until melted, another minute more.

To assemble burgers, spread mayonnaise on toasted bread. Top one slice with cheese-topped patties, bacon, lettuce, and tomatoes. Sprinkle with salt and pepper. Top with second slice of bread. Serve immediately.