I make my own seitan, and the recipe is extensive so I won't list it here. But I do a thick layer of seitan on low-carb bread, a combination of vegan (violife provolone) and dairy (usually sharp cheddar, sometimes gouda or havarti) cheeses, and throw it open-face in an air fryer on the hottest fry setting like they do at subway. While eating it I add small dollops of a homemade sauce similar to chick-fil-a's. It's basically all I need. The seitan I make is phenomenal, and everything else compliments it so well. You don't really notice the bread is low carb when it's part of a sandwich, but it's higher fiber content is both healthy and helps it maintain structure.