I don't have the recipe with me at the moment but the sausages are made from;
Black (?something?) Beans mashed up.
Wheat Gluten Flour
Random Herbs
Other stuff, I can't remember?
But mash them all together and shape then cook
It probably doesn't sound as appealing as a real sausage. But if yo get it right (or buy nice ones) they are really, very good for something that is meat free.