Crockpot Pot Roast

3 medium potatoes, thinly sliced
2 large carrots, thinly sliced
1 onion, sliced
1 2-3lb boneless beef rump roast
1 t salt
1/2 t pepper
1/2 c water or broth

Put vegetables in bottom of pot. Salt and pepper meat, then palce in pot on top of vegetables. Add liquid. Cover and cook 10-12 hours.