Anything I have put in the slow cooker has turned out tender if left in long
enough whether it's pork tenderloin, venison, or anything else. I put the
meat in, add spices I like, cover it with water and let it cook away 21 to
24 hours. When it's done it usually falls apart it's so tender. Just pick
spices you enjoy - my fav combo is cumin, curry, paprika, pepper, tarragon
and then I add fresh tomatoes, too. I typically do not add veggies but you
could to add more flavor to the water. I also use the water it cooked in for
broth either the same day I make the meat or I freeze it in glass jars to
use at a later time.
Hope this helps.
~Kris