Preheat oven to 350F.
Stir together the vital wheat gluten, nutritional yeast, onion powder, garlic powder, paprika, thyme, oregano, and black pepper in a large bowl.
In a separate bowl- whisk together the vegetable broth, soy sauce, olive oil, apple cider vinegar, and tomato paste until well combined.
Pour the wet ingredients into the dry and knead the dough for about 2 minutes or until the gluten has developed and the dough is stretchy- don't over-knead or it'll be too chewy. The dough should be slippery and not dry.
Roll the seitan dough into a long log. Roughly 3x10. Wrap tightly in parchment paper or foil and twist the sides and tuck them under the bottom of the loaf.
Place the wrapped seitan loaf on a baking tray and bake for 90 minutes. The loaf should feel firm. Let completely cool before placing it in the fridge overnight.
Carefully cut the seitan into very thin slices, thick slices, strips, or cubes- whatever you want!