Add about an inch of water to a pot with a steamer basket and bring to a light boil.
In the meantime, whisk together the vital wheat gluten, flour, vegetable broth powder, onion powder, garlic powder, and salt in a medium bowl. Pour in the water and mix to form a ball of dough. Lightly grease the steamer basket, then tear off bite-sized pieces of the seitan dough and place them in a single layer in the steamer basket. Cover, and steam the seitan for 10 minutes.
In the meantime, in a small bowl or a measuring glass, mix together the Thai sweet chili sauce, hoisin, soy sauce, water, rice vinegar, and sesame oil. Set aside. (See notes for other sauce options).
When the seitan is done steaming, heat 2 tablespoons of oil in a large skillet or non-stick pan. Use tongs to remove the seitan bites from the steamer basket, and place them into the hot oil in the pan. Be careful as it may splatter. Cook the seitan bites a few minutes per side until they are golden brown and crispy.
Remove from the heat and add the sauce and toss to coat. Garnish with green onions and sesame seeds if desired and serve hot.* Learn my secret tricks to making perfect seitan in my free masterclass. Click here to learn more and register.