Shape into a loaf, wrap in foil. Place in a steamer basket in a large pot with 3 cups of water. Cover, bring to boil and reduce heat to simmer for 1 hour. Add more water if necessary.
Pro Tip: Seitan is finicky! Check in after an hour to make sure it's cooked, but it can take up to 30 minutes more depending on the size of the loaf. When ready, remove from the foil.