• First prepare the broth in a large pot over medium heat. Combine all ingredients for the broth and let simmer for 30 minutes to develop the flavour profile. Once fully infused, remove the larger chunks with a slotted spoon.
• Preheat oven to 350F.

To make the seitan:

• in a large bowl combine the dry ingredients: gluten, white pepper, onion powder, and garlic powder. Stir to combine.
• In another bowl, combine the wet ingredients: water, tamari, marmite, mushroom broth powder/granules (to dissolve into the water), Worcestershire sauce and oil.
• Add wet ingredients to dry ingredients and stir to combine to create a lumpy dough.
• Once dry ingredients are fully incorporated, turn onto a clean work surface and knead the dough until you have a firmer texture that springs back when you poke it. You'll also find you can tear it slowly when you pull it apart. This will take 5-10 minutes. Feel free to take out your aggression on the dough: punch, karate chop, etc ;)
• Once dough is firm, roll into a rough log and cut into 1 inch thick slabs. Arrange on a lined baking sheet and bake for 25 minutes until golden. Once baked, remove and place directly into the simmering broth and cook on a slow simmer (not too aggressive but not still, hot water either) for 25-30 minutes.
• Once the time has elapsed, remove the seitan slabs from the broth into a container or plastic zip-top bag and add about 1/4-1/2 cup of broth on top to keep the seitan moist. Let chill in the fridge overnight (or for at least 8 hours) for the gluten to continue to develop texture and for the seitan to soak up the flavour.

To cook the lemongrass seitan:

• Once the seitan has set, remove from fridge and slice into thin strips.
• In a large frying pan, saute shallots in oil until translucent. Add minced garlic and saute until fragrant. Add lemongrass and continue to saute until fragrant (about 1-2 minutes).
• Add sliced seitan and stir to coat in the aromatics. If you want to add chile flakes, add them here.
• Add soy sauce and season to taste. Cook the seitan until it browns. You may need to add a few tbsp of water to help deglaze the pan and keep the seitan from drying out.
• Season with black pepper to taste and set aside.

To assemble the banh mi:

• Cut an opening in your baguette, then place in oven or toaster oven for about 2-3 min at 350F until just toasted. Remove and fill baguettes with vegan butter, mayo, cucumber, pickled vegetables, and a generous amount of lemongrass beef seitan!
• Enjoy!