Few cuisines have lamb dishes as delicious as that of Morocco. Because nearly all stews improve with time, you can prepare this dish the day before serving it. Steamed couscous is very good choice with this dish, as is barley, faro, and the small round pasta known as acini di pepe.
A Cru Beaujolais, which offers more heft than the simply light, fruity flavors of a regular Beaujolais, has the kind of red juicy fruit and acidity that will pair nicely with the spice and citrus in this entreé; recommended communes include Morgon, Fleurie, Juliénas and St.-Amour.
4 garlic cloves, crushed, plus 6 garlic cloves, minced
2 teaspoons sweet paprika
2 teaspoons ground cumin
2 teaspoons ground coriander seed
1 teaspoon grated fresh ginger
Freshly ground black pepper
4 lamb shanks, trimmed of outer fat
3 tablespoons olive oil
2 yellow onions, diced
2 cups water, or more as needed
3/4 cup green olives, pitted and sliced
4 preserved lemon wedges, slivered (available at some specialty markets or food stores that feature North African products)
4 preserved lemon wedges, for garnish
Put the crushed garlic cloves in a suribachi or mortar, and add 1 teaspoon of salt. Use a wooden pestle to grind the garlic to a paste. Stir in the paprika, cumin, coriander, and ginger, and several turns of black pepper. Rub some of the mixture over each lamb shank, set on a baking sheet, cover, and refrigerate for several hours or overnight.
Preheat the oven to 300 degrees F.
Pour the olive oil into a large deep pan set over medium heat. Add the lamb shanks and brown them evenly on all sides. Use tongs to transfer the shanks to a plate or baking sheet. Add the onions to the pan, season with several pinches of salt, and cook until they are limp and fragrant, about 15 minutes. Do not let the onions brown. Add the minced garlic and sauté 2 minutes more.
Set the browned shanks on top of the onions and garlic, add 2 cups water, cover the pan, and set on the middle rack of the oven. Bake the shanks until the lamb falls off the bone, about 2 1/2 hours. Check occasionally and add more water if needed. Uncover the pot for the final 20 minutes of cooking. Remove from the oven, cover, and let rest for up to 30 minutes.
To serve, transfer the lamb shanks to a platter. Set the pan over a burner. If there is a lot of liquid left, cook over medium-high heat until it is reduced to about 1/2 cup. Stir in the sliced olives and slivered lemon wedges and pour the sauce over the shanks. Garnish with the remaining wedges of preserved lemons. Serve immediately.