Preheat oven to 350°F.

Mix flour and paprika on a large, flat plate.

Season lamb shanks generously with sea salt and freshly ground black pepper.

Dredge lamb shanks in flour-paprika and set on a plate.

Heat 3 tablespoons of the olive oil over medium-high heat in a large paella or other frying pan with a tight-fitting ovenproof cover.

When the oil is shimmering and easily coats the bottom of the pan, add the shanks and brown on each side until golden - about 3-5 minutes per side.

Remove shanks from the pan and set aside on a plate.

Add the mirepoix - onions, carrot, and celery - and sauté for about 5 minutes to soften the vegetables.

Add wine, 1 cup crushed tomatoes, and citrus zests to the pan. Stir, and bring to a simmer; cook about 5 minutes, until somewhat thickened.

Meanwhile, tie together thyme sprigs, rosemary and bay leaves to make a bouquet garni.

Add to the pan along with the stock. Stir, and bring to a simmer.

Add lamb shanks, cover the pan, and place in the oven. Braise (covered) for about 3 hours, turning shanks every half hour, until lamb is completely tender.

After 2 1/2 hours, add the pitted olives.

After the three hours, remove lamb shanks to a warmed plate and cover with foil.

Remove bouquet garni and discard.

Bring pan with sauce to a simmer. Skim off as much fat as possible.

Add remaining 1 cup crushed tomatoes and reduce heat until sauce thickens.

Serve lamb shanks on polenta or mashed potatoes with a good helping of the sauce on top.

Serve immediately.