Brown ground beef in a large skillet over medium-high heat. Stir in onions, chili seasoning, corn, tomato sauce and water. Heat to simmering.
Combine corn muffin mix, garlic powder and milk in a small bowl. Drop by spoonfuls onto simmering meat mixture. Cover and simmer about 10 minutes or until dumplings are done. (Test for doneness by pressing lightly – dough should spring back).