The seitan cheesesteak at Blackbird is a popular vegan sandwich made with juicy, flavorful seitan slices, a melted cheese-like sauce, crispy onions, and a freshly baked hoagie roll. Some customers have reported that it's a satisfying and delicious sandwich that leaves them craving more. If you're looking for a vegan cheesesteak, Blackbird is a great place to try one out.