To make Rye Bread Stuffing gluten free, replace the marbled rye bread with certified gluten-free rye-style bread or another firm gluten-free bread. Verify that the vegetable broth, dried herbs, butter, egg, and all packaged ingredients are labeled gluten free or free from gluten-containing additives. Use clean mixing bowls, utensils, baking trays, and a clean baking dish to prevent cross-contact with gluten-containing foods.