1 tablespoon finely chopped onion
1 tablespoon ketchup
1 teaspoon prepared mustard
1/4 teaspoon salt
1/8 teaspoon pepper
1/2 pound lean ground beef (90% lean)
1/4 cup finely shredded cheddar cheese
2 hamburger buns, split
Lettuce leaves and tomato slices, optional
In a small bowl, combine the first five ingredients. Crumble beef over mixture and mix well. Shape into four thin patties. Sprinkle cheese over two patties; top with remaining patties and press edges firmly to seal.
Grill, covered, over medium heat for 6 minutes on each side or until a meat thermometer reads 160° and juices run clear. Serve on buns with lettuce and tomato if desired. Yield: 2 servings.