Tips: Try serving meatballs sandwich style, over a bed of rice, pasta or mashed potatoes. Use your leftover meatball sauce for our Broccoli Slaw Recipe Reserve 2/3 cup of sauce from slow cooker meatballs; combine with 1 tsp of rice vinegar and 1 1/2 cups of store bought broccoli slaw. Broccoli Slaw can be found in the bagged lettuce section of most supermarkets. If unavailable, traditional coleslaw mix can be substituted.