This flavorful chicken taco casserole is packed with veggies, chicken, cheese and crispy tortilla chips and baked to perfection, then topped with fresh tomatoes, crisp iceberg lettuce and creamy avocado—just like a classic taco. Make it your own by swapping out the black beans for pinto beans or adding pepper Jack cheese for some added kick. If you want to keep it mild, opt for a milder taco seasoning and skip the jalapeños.