• 2 large green cabbages (about 3 pounds each), cored and finely chopped
• 2 bunches watercress (stems removed), rinsed
• 3 medium onions, finely chopped
• 4 celery ribs (leaves included), finely chopped
• 1 teaspoon dry mustard
• 1 teaspoon salt
• ½ teaspoon freshly ground black pepper
• ½ teaspoon cayenne pepper
• One 10-pound precooked ham shank

Place the cabbage, watercress, onions, celery, dry mustard, salt, pepper, and cayenne pepper in a stockpot or roasting pan large enough to fit the ham. Add enough water to reach within 1 inch of the top of the vegetables, stir, and bring to a boil. Turn off the heat, cover the pot, and let the vegetables stand 10 minutes in the hot water. Drain the vegetables in a colander over a bowl to catch the broth, let cool, and reserve the broth.

With a sharp knife, cut Xs about 1 inch square and 2 inches deep all over the ham and fill each X with vegetable stuffing. Wrap the ham in a wide double thickness of cheesecloth and tie the ends to secure it tightly.

Place the ham in the pot along with the reserved broth and add enough water to cover. Place a lid on the top, bring the liquid to a boil, reduce the heat to low, and simmer the ham for 2 to 2½ hours, adding water as needed to keep it covered. Turn off the heat and let the ham cool in the liquid, preferably overnight.

When ready to serve, reheat the ham in its liquid, transfer to a cutting board or large platter, remove and discard the cheesecloth, and cut in thick slices.