Buttered egg noodles or mashed potatoesfor serving
Instructions
Add the frozen meatballs, beef stock and soup mix to the slow cooker. Stir to combine. Cook on HIGH for four hours.
Mix together the cornstarch and just enough beef stock or water to dissolve the starch (1-2 tablespoons).
Add the cornstarch mixture, sour cream and mustard to the slow cooker and carefully stir until mixed. Cook for 30-60 minutes more, until mixture is thickened.
Serve with mashed potatoes or egg noodles according to preference.