Preheat oven to 350°F (175°C) and cut 8 squares of parchment paper about 10 x 10 inches in size. Set aside.

In a food processor or blender, pulse up the oats until they are broken up and a mix of floury and small pieces. Tip them into a mixing bowl, add the vital wheat gluten and mix together.

Peel and cut the onion into a few smaller pieces then add it to the food processor/blender (there's no need to wash the bowl first). Add all of the other ingredients and blend until pretty much smooth.

Pour the wet mixture into the dry and stir well with a spatula until mostly combined. There will still be some dry bits that won't mix in. Tip out onto a clean surface and knead for about 1 minute or until there are no dry bits showing, and a dough is formed.

Divide into 8 even pieces and shape into rough 1½ inch diameter sausage shapes. They won't look pretty or perfect at this stage (more like poops 🤣) but don't worry it gets better!

Roll each sausage up tightly in a piece of parchment paper, at first tucking it over and slightly under the sausage to secure it before rolling all the way. (There are pictures in the post above to show this process).

Once rolled all the way up, twist both sides really tightly like paper wrapped caramel candies. It's the rolling and the twisting that compacts the seitan sausage dough and neatens them into proper sausage shapes.

Tear a piece of foil about double the length of all your sausages lined up. Sit the sausages on one end of it then lift the other side of the foil up and over to cover them. Squeeze the edges tightly shut all the way around to create a seal.

Place on a baking tray and bake for 30 minutes then carefully turn the foil packet over and bake for another 30 minutes.

Remove from the oven, and use as needed or allow to cool in their parchment paper wrappers.