To make this Amish Country Casserole gluten free, replace the egg noodles with certified gluten-free egg noodles or another gluten-free pasta shape. Verify that the tomato soup, cream of mushroom soup or cream of chicken soup, Worcestershire sauce, dried onion flakes, Parmesan cheese, and all packaged ingredients are labeled gluten free or free from gluten-containing additives. Use clean cookware, utensils, measuring tools, and a clean baking dish to prevent cross-contact with gluten-containing ingredients.