Measure all of the dry ingredients (wheat gluten, flour, garlic powder, onion powder, herbs, and salt) into a large glass bowl and stir until well combined.
Stir in 1 cup of vegan broth with a silicone spatula, then knead with your hands until all of the flour is incorporated. (You may have to add a tablespoon or two of water to the dough to get all of the flour incorporated.)
When you have a firm rubbery dough, bring 3 cups broth and 3 cups water to a boil. Rip off small walnut-sized pieces of dough and drop them into the hot broth. (They will double in size when cooked.)
Cover with a lid and turn the heat to low and simmer at a slow boil for 35 minutes. Then turn off the heat and allow it to cool for about 1/2 hour.
Transfer the cooked seitan along with the broth to a container with a lid and store in the fridge until ready to use. (You can use it immediately, but it will be firmer and more meat-like the next day.)
Cut up cooled seitan and toss it into any meal. Use as you would pre-cooked meat in any recipe.
Notes
The texture of the seitan will continue to firm up and become more meat-like if allowed to cool overnight in the fridge. However, you can use it after it simmers if you don't want to wait.
Use less salt and low sodium broth for lower sodium seitan.
Flavor VariationsChicken Seitan - Use poultry seasoning in the dough and not chick'n broth to mix the dough and simmer the seitan.Beef Seitan - Use oregano to season the dough and not beef broth to mix into the dough and simmer the seitan. (You can also use vegetable broth with 1 teaspoon of soy sauce added for each cup of broth to make a beef-style broth.)