Cooking lamb in a slow cooker without water?

I have done this before, I put broth in my crockpot and it made the meat soooo tender and it just fell apart. It was really great! but if you do it with no liquid then it will dry up. Id say use the broth and cook it for about 8 hours on medium/low heat. oh and the potatoes will cook perfectly as long as you put them in atleast 6 hours (they go all 8 hours though) you could even throw some carrots in too!