Mix the vital wheat gluten, nutritional yeast flakes, garlic powder and minced garlic in a bowl and mix. Add 1 cup vegetable stock, and soy sauce and mix until forms a ball. Once in a ball kneed by hand for two minutes.
Once kneeded either form into a loaf or cut into small bite sized pieces. Remember the seitan will double in size when cooking.
Place the seitan in a pot with the remainder of the cold vegetable stock and onion. Bring to a boil then turn down the heat to a low simmer. Cover and cook for 45 minutes.
After the 45 minutes remove the seitan from the vegetable stock and cool. Once cooled you can use this in replacement for meat in your favorite recipe.