Place avocados in a medium bowl. Add ⅓ cup salsa and sour cream; mash to chunky guacamole consistency. Season with lime juice, salt and pepper.
In a large glass bowl, layer half of lettuce, chicken, chips, beans, green onions, bell pepper and cheese. Top with all of the guacamole and all of the remaining salsa. Repeat layering with remaining ingredients.
Let guests scoop up their own salad and drizzle buttermilk salad dressing on top of individual servings.
Notes
If preparing this recipe as GLUTEN FREE, just be sure to use a brand of tortilla chips that is designated as GF, and use your favorite GF salad dressing.
This salad may be prepared up to 2 hours ahead (no more than that or the chips and guac will get icky), just cover and chill.