1Heat oven to 350°F. In 10-inch skillet, cook beef over medium heat 8 to 10 minutes, stirring occasionally, until thoroughly cooked; drain. Stir in beans and 1 cup salsa. Heat to boiling, stirring occasionally.
2In ungreased 2-quart casserole, place broken tortilla chips. Top with beef mixture. Spread with sour cream. Sprinkle with onions, tomato and cheese.
3Bake uncovered 20 to 30 minutes or until hot and bubbly. Arrange whole tortilla chips around edge of casserole. Serve with lettuce and salsa.