Grilled Leg of Lamb with Spicy Citrus Glaze

The day before cooking the leg of lamb, remove it from the packaging. Remove and discard the netting surrounding the meat. Place the lamb on a cutting board and unfold it so it lays flat. Using a sharp knife, cut the meat in half crosswise to create 2 halves of approximately equal size and shape. 

Using a spice grinder or a mortar and pestle, grind the coriander seeds and peppercorns to a medium-coarse grind. Transfer to a small bowl and add the salt, ginger, lemon zest and garlic. Add the olive oil and stir to make a paste. Rub about three-fourths of the spice mixture evenly onto the meat side of the lamb. Turn the lamb over and rub the remaining spice mixture onto the fat side of the lamb. Place the 2 pieces together, meat side to meat side, in a baking dish, cover with plastic wrap and refrigerate for 24 hours.

About 1 hour before grilling, remove the lamb from the refrigerator and separate the 2 pieces. 

Meanwhile, prepare the glaze: In a small saucepan over medium-low heat, combine the marmalade, lemon juice, mustard, piment d’Espelette and salt. Heat until the marmalade has liquefied and the mixture comes to a gentle simmer. Remove from the heat. Transfer 1 cup of the glaze to a bowl and reserve for serving. Keep the remaining glaze in the saucepan; cover and keep warm.

If using a charcoal grill, light the coals and build a mound of them on one side of the grill. The amount of coals should equal about one-third of the total grill surface and be about 3 inches below the grill surface. If using a gas grill, preheat half of the grill over high heat. 

Place the lamb pieces, fat side down, on the grill over direct heat and cook until well seared, about 5 minutes. Turn the lamb so it is meat side down and sear until grill marks appear, about 5 minutes more. Move the lamb to the cooler side of the grill, placing it meat side down and with the thickest part arranged 2 to 3 inches from the fire. Cover the grill and cook the lamb over indirect heat, maintaining an internal grill temperature of about 400°F. After 10 minutes, uncover the grill and brush the lamb all over with a light coating of the glaze from the saucepan. Cover the grill and cook until an instant-read thermometer inserted into the thickest part of the lamb registers 128°F, 15 to 20 minutes more.

Transfer the lamb to a cutting board, cover loosely with aluminum foil and let rest for at least 15 minutes before carving. Cut the lamb against the grain into slices 1/4 inch thick and transfer to a warmed platter or individual plates. Brush the lamb slices with the reserved 1 cup glaze just before serving. Serves 6 to 8.

Adapted from a recipe by Thomas Keller, The French Laundry.