When I do a slow cooked leg of lamb, I don't use a slow cooker but a dutch oven for 6 hours but anyhoo I add bacon on the bottom, a cup of vegetable stock, a cup of white wine and then cut up onions and garlic to float around in the water! It's yummo and then I use the fluid to make the gravy and to cook potatoes and carrots for the last 30 mins.