In a large oven pot with cover, coat with olive oil and sautee ginger, onions and garlic over medium heat. Add the greens and pack them in the pot. They will shrink big time in the oven. Season well and add the chicken stock and vinegar. Cover and place in oven for 45 minutes. Check after 20 minutes, verify flavor and stir.
PLATING Slice thick pieces of prime rib and place on top of a pile of mashers. Place a small mound of greens and sauce the plate.