In 1 1/2-quart microwavable casserole, crumble beef. Cover loosely; microwave on High 2 minutes 30 seconds to 3 minutes 30 seconds or until beef is thoroughly cooked. Stir and drain.
Stir in onion, beans, tomato sauce, seasoning mix, pepper sauce and garlic. Cover tightly, microwave on High 3 minutes. Stir, spread mixture in 9-inch microwavable pie plate. Cover, microwave on High 3 to 4 minutes or until hot and bubbly.
In small bowl, mix sour cream, 2 tablespoons Cheddar cheese and the chili powder. Spread over beef mixture. Sprinkle with lettuce and remaining Cheddar cheese. Serve with tortilla chips.