Ham Hock StockCombine all the ingredients in a small stockpot. Bring it up to a boil and cover. Cook for about 2½ hours at a simmer. The ham hock should be very tender, the meat easy to pick off the bone. Let the ham hock cool in the liquid for at least 30 minutes.Strain out the vegetables. Reserve the stock (there should be 2 quarts) and skim off any fat that congeals at the top. Pick and slightly shred the ham hock meat and reserve.Turnip Root and Green DressingPreheat your oven to 350 degrees and grease a 9×13×2-inch baking dish with 1 tablespoon butter. Bring the stock to a boil and set up an ice bath nearby. Drop in the diced turnip roots and cook until just tender, about 4 minutes. Shock them in the ice bath.Drop in the turnip greens and cook them also for about 4 minutes. Once they are just barely tender, transfer them to the ice bath as well. Reduce the ham hock stock to about 3 cups. Drain the roots and greens and pat them dry.Melt 1 tablespoon of butter in a medium sauté pan and sweat the onion, celery, and garlic with 1 teaspoon salt for about 10 minutes, or until translucent and shrunken slightly.In a large bowl, toss together the onion mixture, the ham hock meat, turnip roots and greens, cornbread, 1 cup Parmesan cheese, and the remaining salt and the pepper until well combined. Pour the ham hock stock over to moisten. Transfer all of this to your baking dish and press down on it slightly. Dot the top of it with the remaining butter and sprinkle with the remaining cheese.Bake uncovered for 1 hour.