1 tsp. dry mustard
1 tsp. warm water
1 lb. ground beef
1 c. chopped tomatoes
1 c. finely chopped fresh mushrooms
2 tsp. minced onion
1/4 tsp. pepper
1/8 tsp. garlic powder

Mix mustard with water. Let stand for 10 minutes. Combine mustard with remaining ingredients and mix well. Shape into 6 patties. Broil until desired doneness is obtained.