Into a casserole dish combine 1 lb. Browned ground beef, 1 med. Chopped onion, 1 8 oz. Can tomato sauce, 1/4 c. Water, 1 tsp. Chili powder, 1/4 tsp. Salt, 1/2 tsp. Garlic powder, 6 - 6 in. Tortillas cut into wedges, and 4 oz. Shredded cheese. Cook 6 to 8 min on high. Let stand 5 min.