Vital wheat gluten is essential to this recipe, and there is no substitute. Therefore this recipe cannot be made gluten-free. For a vegan gluten-free meatball recipe try my bean ball recipe in Fuss-Free Vegan which has a gluten-free option.
Steaming tips: you need to steam the vegan meatballs before using them. I recommend getting a steamer pot if you plan to make seitan often, or you can use a DIY method if you do not have a steamer.
Cleaning tips: vital wheat gluten is very sticky and can destroy dish brushes and cloths. So what I like to do is save old clothes, sheets, or towels that are too shabby to donate, and cut them into rags. I use these rags to clean up after preparing a seitan recipe and discard the rag once finished.