Preheat oven to 350°F. With a sharp knife, loosen the meat from the bone slightly. Rub the pepper, sage and rosemary all over the outside of the hock. In an oven proof pan or roaster, brown the hock well on all sides. Pour some of the stock or broth over the ham hock and add all the vegetables (onion, carrot, celery root, parsley root or parsnip) and peppercorns.
Place the pan or roaster in the oven and roast for 1 1/2 to 2 hours, basting with broth every 15 minutes or so. Add more broth if necessary, so the pan doesn’t dry out.
Remove the ham hock and cover with foil to keep warm. Place the roasting pan over medium heat and scrape all the roasted bits from the bottom. Strain the broth -- you should have about two cups, so add more if needed. Stir the flour into the sour cream and then add the sour cream to the hot broth in the pan. Season to taste with salt, pepper and white wine. The white wine cuts the fat taste, so start with a few tablespoons, taste, and add more if needed.
Remove the meat from the bones and serve with the sauce. For a very traditional presentation, enjoy with potato dumplings and sauerkraut or creamed cabbage.
Variation: After braising and removing meat, discard the peppercorns (hint-- strain vegetables from broth first to find the peppercorns-- much easier than hunting in the full fat of broth). Blend the vegetables into the broth using a hand blender or potato masher. Add in sour cream, flour, salt, pepper and white wine to taste. Shown in picture.