1Heat oven to 375°F. In 12-inch nonstick skillet, cook beef and onion over medium-high heat 5 to 7 minutes, stirring occasionally, until beef is brown; drain. Stir in black beans, mixed vegetables and salsa. Heat to boiling; cook over medium heat 5 minutes, stirring occasionally.
2In ungreased 2-quart casserole or 8-inch square (2-quart) glass baking dish, spread beef mixture. Make muffin mix as directed on pouch, using 2 tablespoons milk, 2 tablespoons butter and the egg. Drop batter by 8 spoonfuls onto chili mixture.
3Bake uncovered 20 to 25 minutes or until topping is golden brown.