Go over to my Vegan Chicken-Style Seitan recipe (link above) and follow instructions for step 1- skipping the dredge & the lemon garlic sauce. Make day ahead or fresh. See notes above for more information. Once cooked, drain on a wire rack and set aside.
Whisk together the remaining ingredients listed under Vegan Tandoori Chicken. Add the seitan patties to the yogurt and spice mixture and let marinade for minimum 20 minutes (or overnight).
Now, let's make the yogurt herb sauce. Simply whisk together the unsweetened yogurt, garlic, onion powder, salt, pepper, parsley, cilantro, and mint until well combined. Cover and place in fridge until ready to serve.
Thinly slice the cucumber, carrots, and red onion. I used a peeler to make long ribbon-like pieces of cucumber and carrots. Toss with lime juice, if desired. Roughly chop cilantro. See note above for more topping ideas!
Heat a large pan on medium-high with a thin layer of oil coating the bottom. Add the marinaded seitan to the hot pan and cook for 3-5 minutes on each side. Remove and place back on wired rack. *Only cook the seitan that you plan to serve immediately. Store leftovers in the fridge.
Toast the hamburger buns. Add the tandoori chicken patty, all the toppings, and a healthy drizzle of the yogurt sauce. Serve!