To ensure that this Roasted Cabbage Steaks recipe is gluten-free make sure that all of your ingredients including the spices are certified as gluten-free. Although many spices and seasonings are naturally free of gluten there is a possibility of cross-contamination, during processing. Moreover, it's important to check that the paprika, garlic powder and red pepper flakes you use do not contain any added gluten. By taking these precautions you can enjoy a gluten-free version of this dish without compromising its flavor or texture.