In a slow cooker, combine melted butter, chicken, onion, prosciutto and wine (or juice/vinegar).
Cover and cook on LOW for 7 to 9 hours or until chicken is cooked through. About 30 minutes before serving, combine cornstarch and water; add to slow cooker along with the cream; blend well.
Cover and cook on HIGH until sauce thickens.
LC SERVING SUGGESTION: Serve over Cauli-Rice (see Day 4 directions); add steamed green and yellow (wax) beans.