In skillet, saute salt pork or bacon and onion until golden brown; drain. Put into crockpot with clams.
Add remaining ingredients, except half and half or milk and cornstarch.
Cover; cook on high 3 to 4 hours or until potatoes are tender.
During the last hour of cooking, combine 1 cup half and half with cornstarch. Add with the remaining half and half; stir well. Heat through.
Serve in large bowls with French bread, if desired.