I searched and searched for a vegetarian taco soup recipe and found a few, but none were for the slow cooker. I also could not find any that were very quick and easy to prepare.
I finally took this recipe and made it without the ground beef. About an hour before the recipe was done I added 1/3 cup of re-hydrated TVP (textured vegetable protein). I think you could also make this recipe with frozen vegetarian crumbles as well.
It was really good! I served it over some fritos with some low-fat shredded cheese & avocado on top.