1 1/2 lbs. ground beef
1/4 c. catsup
1/4 c. water
1 tsp. minced onion
1 tsp. Worcestershire sauce
1/2 tsp. salt
1/4 tsp. liquid smoke
Cheese slices

Mix all ingredients except cheese. Shape into 6 patties. Grill on medium 5 to 7 minutes each side. Top with cheese slices when done.