Heat oven to 350 degrees.
To make salsa: In medium bowl, combine avocado, lime juice, cilantro, garlic, chilies and red onion; toss to thoroughly mix. Add watermelon and toss gently. Set
aside. Over medium heat, heat beans until hot. Mash if preferred. Place chips on flat, oven-proof plate or cookie sheet and top with beans and cheese.
Repeat layers as desired. Heat in oven for 10 minutes,
or until cheese has melted and chips are hot. Top with salsa mixture and sour cream. (Tip: Reserve some salsa to place in bowl for dipping.)