Taco Casserole

Ingredients

• 1 lb. ground beef
• 1 medium onion, chopped
• 1 (8 oz.) can tomato sauce
• 1/4 c. water
• 1 tsp. chili powder
• 1 (16 oz.) can refried beans
• 1 (6 oz.) pkg. Monterey Jack cheese, shredded
• 5 taco shells or tortilla chips, coarsely crushed
• 1 small tomato, chopped
• 1/4 c. sliced green onion
• 1/4 c. sliced pitted olives
• 1 (6 oz.) carton avocado dip
• 1 c. shredded lettuce