In skillet, sauté 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.