Spread beans in 9x13-inch baking dish. Combine mayonnaise and sour cream; spread over beans. Sprinkle chopped avocados with lemon juice.
Layer over mayonnaise mixture. Cover with picante sauce. Sprinkle with cheeses, then onions. Top with olives.
Bake, uncovered at 350° for 30 minutes. Serve with tortilla chips.
Servings: