Yes and no. You can, and I have, but the best way is definitely on the stove top. The mushrooms add a fair amount of moisture and the dish feels more watery and less flavorful when only cooked in the crock pot. However, you can do the majority of the cooking in the crockpot and then finish them on the stovetop. It's less time spent hands on, but more dishes, so that's the trade off there.