Dough: In a large bowl stir together all dough ingredients until a ball forms. Transfer to a clean surface and knead for about 5 minutes, or until dough is elastic and cohesive (it will still be lumpy, that's okay!)
Shape: Portion dough into about 25 pieces, then roll into small balls (they will expand when cooking, so make them smaller than you think you'll want them!). Let meatballs rest while you prepare the broth.
Broth: Add all broth ingredients to a large pot and bring to a simmer. Gently lower the seitan meatballs into the broth, ensuring the dough is covered by the broth (if not, transfer to a smaller pot). Partially cover and simmer for 30 minutes.
Saute: Remove from pot and let cool enough to touch. Heat oil in a large saute pan over medium heat, then add the meatballs. Cook, jostling the pan often, until meatballs are golden brown on all sides. Serve with marinara sauce and your favorite pasta!