Peel and dice 1 small onion and wash and slice 2 cups of mushrooms. Then add 2 tablespoons of oil to a large skillet and saute the diced onion, sliced mushrooms, and 1/4 tsp salt.
Add 2 tsp smoked paprika, 1 tsp oregano, 1/2 tsp black pepper, 1/2 tsp garlic powder, 1/4 cup soy sauce, and 2 tbsp tomato paste, and mix well. Then stir in 1 cup of water and turn off the heat.
Transfer the mixture to a food processor or blender and puree.
Pour the pureed mixture into a large glass bowl add 1 1/2 cups of vital wheat gluten and stir with a silicone spatula.
Kneed in the last 1/2 cup of wheat gluten with your hand until a firm dough ball is formed.
Shape your dough ball into a loaf shape and wrap it tightly in thick foil.
Place the wrapped roast in a steaming basket and steam for 1 hour and 15 minutes. (Or in a pressure cooker or Instant Pot for 55 minutes and then let the steam escape naturally.)
You can now use it for a seitan roast beef, a vegan pot roast, slice it up for vegan Mongolian beef or use the seitan strips in a lettuce wrap. (Allow the vegan beef to cool for about 15 minutes before slicing.)
Notes
Use a glass bowl and a silicone spatula to mix your seitan. Vital wheat gluten is very sticky once it gets wet and will stick like glue to a plastic bowl or a wooden spoon.
Wheat gluten is a very fine powder that will get everywhere if you are not careful with it. Pour it low down and slowly over the broth mixture so it doesn't splash out of your bowl.
Knead the seitan until all of the gluten flour is incorporated and you have a dough that's a little firmer than you would have for bread. Only knead it for about 60 seconds so your wheat meat doesn't get too chewy.
If you don't want the foil to touch your food, you can wrap the mock beef in parchment paper first, and then wrap the foil around that.
Seitan expands when it cooks, so be sure to use strong foil, or it will break the foil when it is steaming.
Be sure to steam the seitan for a full hour and 15 minutes. The internal temperature needs to reach 160° F.
If you are going to bake the roast after steaming to make my vegan pot roast or vegan roast beef recipes, you only need to steam it for 1 hour since it will heat the rest of the way in the oven.