From America's Test Kitchen Season 5: Winter Supper
Osso buco, veal shanks braised in a rich sauce until tender, is incredibly rich and hearty. We felt that this time-honored recipe shouldn’t be altered much, but we hoped to identify the keys to flavor so that we could perfect it.
To serve one shank per person, we searched for medium-sized shanks, and tied them around the equator to keep the meat attached to the bone for an attractive presentation. Most recipes suggest flouring the veal before browning it, but we got better flavor when we seared the meat, liberally seasoned with just salt and pepper. Browning in two batches enabled us to deglaze the pan twice, thus enriching the sauce. Celery, onion, and carrots formed the basis of the sauce; for the liquid we used a combination of chicken broth, white wine, and canned tomatoes. The traditional garnish of gremolata—minced garlic, lemon, and parsley—required no changes; we stirred half into the sauce and sprinkled the rest over individual servings for a fresh burst of citrus flavor.
To keep the meat attached to the bone during the long simmering process, tie a piece of twine around the thickest portion of each shank before it is browned. Use a zester, vegetable peeler, or paring knife to remove the zest from a single lemon, then mince it with a chef's knife. With the lid on the pot cracked, the braising liquid should reduce to a sauce-like consistency in the oven. Just before serving, taste the liquid and, if it seems too thin, simmer the liquid on the stovetop as you remove the strings from the osso buco and arrange them in individual bowls.