To make this recipe gluten free, use certified gluten-free tortilla chips and verify that the taco seasoning, cream of chicken soup, Rotel tomatoes, black beans, shredded cheese, salsa, and sour cream are all labeled gluten free or free from cross-contact concerns. If needed, replace the canned cream of chicken soup with a homemade gluten-free cream sauce or a certified gluten-free condensed soup alternative. When preparing the casserole in a shared kitchen, use clean utensils, cookware, and baking dishes to help avoid gluten contamination.