1 1/2 lbs. ground round
1/2 c. chopped water chestnuts
1/2 c. cubed Cheddar cheese
1 sm. onion, finely chopped
2 tbsp. chili sauce
1 1/2 tsp. Chinese hot mustard
2 tsp. soy sauce
6 hamburger buns, toasted and buttered

Combine all ingredients except buns; shape into patties. Grill over medium heat for 5 minutes per side for rare, 10 minutes for medium.