Cheesy Stuffed Burgers

• 1 tbsp finely chopped onion
• 1 tbsp ketchup
• 1 tsp prepared mustard
• 1/4 tsp salt
• 1/8 tsp pepper
• 1/2 lb lean ground beef
• 1/4 cup finely shredded cheddar cheese
• 2 hamburger buns, split
• 1 lettuce leaves, optional
• 1 tomato slices, optional

1. In a small bowl, combine the first 5 ingredients.
2. Crumble beef over mixture and mix well.
3. Shape into 4 thin patties.
4. Sprinkle cheese over 2 patties, top with remaining patties and press edges firmly to seal.
5. Grill, covered, over medium heat for 6 minutes on each side or until a meat thermometer reads 160 and juices run clear.
6. Serve on buns with lettuce and tomato if desired.

onion, ketchup, mustard, salt, pepper, lean ground beef, cheddar cheese, buns, lettuce leaves, tomato

Taken from cookpad.com/us/recipes/348749-cheesy-stuffed-burgers (may not work)