Preheat oven to 400ºF. Line a baking sheet with parchment paper and brush lightly with about a tablespoon of olive oil. In a food processor, lightly pulse seitan, nuts, mushrooms, onion and garlic together until crumbly. Do not over process! Add breadcrumbs, herbs, remaining olive oil, nutritional yeast, tamari and salt and pulse again until combined. Let stand for 5 to 10 minutes.

Using your hands or a portion/ice cream scoop, shape mixture into balls of desired size, a good size is about 2 to 3 inches in diameter, unless you want to make Wheatball Sliders using small rolls, then make smaller wheatballs. Place on baking sheet and bake for 20 minutes or until lightly browned. Alternatively, you can fry these in a little oil, but be gentle, wheatballs are a little delicate. If frying, let the oil warm up in the pan first before gently placing about 4 wheatballs in the pan. Let them brown on one side before gently sliding the spatula underneath and rolling over. Repeat until all sides are brown then remove from pan then repeat with remaining wheatballs.

Cut the bread into desired portions and split down the middle. With the bread opened on a baking sheet, spread a couple of tablespoons of sauce on one side then place wheatballs on top. Spoon more tomato sauce on top, then sprinkle vegan mozzarella cheese on top. Repeat till all the wheatballs are used. Place baking sheet in the oven on the top rack for 5 to 10 minutes, or until vegan cheese is lightly browned. Alternatively, serve with pasta instead or bread, or use spaghetti squash for an even healthier meal.