MIX broth, dressing, barbecue sauce and oregano in slow cooker. Add all remaining ingredients except flour and water; toss to coat. Cover with lid. Cook on LOW for 8 to 9 hours (or on HIGH for 4 to 5 hours).
TRANSFER meat and vegetables to serving bowl with slotted spoon; cover with foil. Set aside.
MIX flour and water until well blended. Stir into juices in slow cooker; cover. Cook on HIGH for 15 min. or until sauce is slightly thickened. Spoon over meat and vegetables.