For the wet mix loaf: Pour 8 cups of water into a large pot, then drop in mushrooms, liquid aminos, vegan chicken bouillon, salt and pepper, and bring to a simmer, then let cook until mushrooms are soft, about 45 minutes.
Strain the mushrooms and keep the broth in a separate container. Let broth cool in the freezer for 1 hour.
For the dry mix loaf: Add vital wheat gluten flour, onion powder, garlic powder and cayenne to a mixing bowl and mix it together. Slowly add the mushroom broth, pouring until the seitan loaf is firmly stretchy. (See Cook's Note.) Roll seitan loaf into a football shape. Wrap in plastic and let it relax.
Bring a pot of water to a boil. Drop the seitan loaf in the water water and drop the temperature; simmer, covered, 1 hour. Remove loaf to a plate and refrigerate, 1 hour.
For the dredge: Place the flour, flaxseed meal, salt, and 4 cups water in a mixing bowl and mix together into a thick batter. Put some panko in another bowl.
Cut the seitan loaf with a serrated knife into 4 1/2-by-3-inch slices that are 1 1/2 inches thick. Coat seitan patties in dredge, then bread in panko.
Bring oil to 350 degrees F in a deep-fryer and deep-fry patties for 30 to 45 seconds, or cook in some vegetable oil in a frying pan over medium heat, 7 minutes per side.
For the avocado sauce: Blend the flesh of the avocados with the oil, salt and 1 cup water until you have a smooth consistency.
For assembling the torta: Mash black beans in a bowl.
Split the rolls to make sandwiches. Add beans to the bottom pieces, then place patties on top. Add cabbage, sliced tomatoes, avocado sauce and vegan mayo.
Make sure to add the mushroom broth very slowly, only until you get a firm loaf.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Lick It Up Food Truck, El Paso, TX