I ended up adding an additional cup of water, and it was still quite stiff. (catchingseeds.com)
From here, you can either heat them through for another 15 minutes on the stove, then finish with the breadcrumbs, or add an additional cup of water / broth, scatter that breadcrumbs on top and bake it in a 350 °F oven for 20 minutes until the sausage is heated through. (smittenkitchen.com)
If you want to cook the quinoa in the soup instead of separately, add two additional cups of water or broth to the soup because the quinoa will absorb it while it cooks. (staceyhomemaker.com)