Braised Lamb Shanks with Pickled Red Onions and Mashed Potatoes

Steps

1. Pickle the onions first. Dissolve the sugar and salt in the warm water, then stir in the vinegar. Put the peppercorns and bay leaf in a glass jar, pack in the onions, and pour the brine over to cover. Rest at least 1 hour, in glass or ceramic rather than metal.
2. Season. Set a rack in the lower-middle of the oven and heat it to 285°F. Pat the shanks dry and season them all over with the salt and pepper.
3. Sear. Heat the oil in an enameled Dutch oven over medium-high until shimmering. Brown the shanks well on all sides, 8–10 minutes total. Set them aside.
4. Cook the aromatics. Pour off all but about 1 tbsp fat. Over medium, cook the onion, carrot and celery until soft, 5–6 minutes. Add the garlic and tomato paste and cook 2 minutes, until the paste darkens.
5. Deglaze. Add the wine, scrape up the browned bits, and simmer until reduced by about half, about 5 minutes. Add the stock, rosemary, thyme and bay leaf.
6. Assemble. Nestle in the shanks. The liquid should reach two-thirds of the way up the shanks; add stock or water to get there. Bring to a bare simmer on the stove.
7. Cover. Cut a parchment circle the diameter of the pot with a small vent in the center and press it onto the surface of the liquid. Put the lid on. If you have a probe thermometer, sink the tip into the liquid beside a shank, not touching bone or pot, with the wire under the lid’s edge. Move the pot to the oven.
8. Braise. The target is liquid at 190–200°F. If it holds at a rolling boil, drop the oven 15–25°F. At 90 minutes, turn the shanks and check the level; top up with hot stock if it is below halfway.
9. Brown. At about 2½ hours, remove the lid and parchment. Cook uncovered 30–45 minutes, turning once. The shanks are done when a fork slides in with no resistance and the meat pulls from the bone; if not, keep going and check every 20 minutes. Total time is 3–3½ hours.
10. Make the sauce. Move the shanks to a plate and tent with foil. Strain the liquid, pressing on the solids. Let it settle 5 minutes and skim the fat. Reduce over medium until it coats a spoon, about ¾ cup. Off the heat, swirl in the butter and season. Return the shanks and baste.
11. Boil the potatoes. About 40 minutes before the lamb is done, cover the potatoes by 1 in with cold, well-salted water. Bring to a boil, then simmer until a knife slides in with no resistance, 20–25 minutes.
12. Mash. Drain, then return the potatoes to the pot over low heat for 1–2 minutes to steam off moisture. Mash, stir in the butter first, then the warm milk a splash at a time. Season.
13. Serve. Spoon the mash onto plates, set a shank on top and spoon over the sauce. Drain a portion of onions, toss with the parsley, and pile alongside.