2 T. olive oil
4 lamb shanks, about 1 lb. (500 g.) each
Salt and freshly ground pepper
1 carrot, finely chopped
1 yellow onion, finely chopped
2 celery ribs, finely chopped
3 small sprigs fresh thyme
1 bay leaf
3 cloves garlic, minced
1 1/2 T. tomato paste
2 cups (16 fl. oz./500 ml.) dry white wine
1 cup (8 fl. oz./250 ml.) chicken broth
Grated zest and juice of 1 lemon
Grated zest and juice of 1 lime
Grated zest and juice of 1 orange

In a large, heavy pot, heat 1 tablespoon of the oil over medium-high heat. Season the shanks with salt and pepper. Working in batches, sear the shanks, turning as needed, until browned on all sides, 6-8 minutes. Transfer to a platter and pour off the fat from the pot. Preheat the oven to 250 degrees F (120 degrees C). Add the remaining 1 tablespoon oil to the pot and place over medium-low heat. Add the carrot, onion and celery and sauté until softened, about 5 minutes. Add the thyme, bay leaf, and garlic and tomato paste. Stir in 1/2 teaspoon salt, season with pepper, and stir for 1 minute. Add the wine, broth and lemon and lime zests and juices. Return the shanks to the pot and bring the liquid to a gentle simmer. Cover and cook in the oven, turning the shanks every hour, until the meat is completely tender, about 2 1/2 hours. Transfer the shanks to a platter and keep warm in the oven. Pour the juices from the pot into a large, heatproof measuring pitcher and let stand for 1 minute. The fat will rise to the top. Use a bulb baster to transfer the juices underneath the fat to a small saucepan. Simmer to reduce slightly. Stir in the orange zest and juice. Drizzle the reduced juices over the lamb shanks and serve. Serves 4.