In skillet, saute bacon and onion until golden brown. Drain, and put into slow cooker.Add all remaining ingredients, except half and half (or cream), cornstarch, and parsley.Cover and cook on high 3 to 4 hours, or low 6-7 hours, until vegetables are tender.During the last hour of cooking, combine 1 cup of milk or cream with the cornstarch. Add cornstarch mixture and the remaining milk or cream and stir well; heat through.Garnish with parsley.