There are several options when it comes to adding protein to your stir-fry. My favorite addition is crispy air fryer tofu. The tofu can be cooked in the air fryer, while you're cooking the stir-fry, and needs very little hands-on time. It adds a nice texture to the vegan stir-fry. But if you don't like tofu you could opt for TVP (textured vegetable protein). The TVP cooking process is simple.