For the ribs:

• 1 Tbsp. ground coriander
• 1 Tbsp. ground cumin
• 1 Tbsp. smoked hot paprika
• 1½ tsp. kosher salt
• 1 tsp. freshly ground black pepper
• 1 tsp. ground cinnamon
• ½ tsp. ground cardamom
• ¼ tsp. ground cloves
• 2 racks of lamb ribs (3¼ lb. total), cut Denver-style

For the harissa barbecue sauce:

• ½ cup ketchup
• 2-3 Tbsp. harissa paste
• 2 Tbsp. honey
• 2 tsp. Dijon mustard
• 2 Tbsp. sherry vinegar
• 2 tsp. Worcestershire sauce
• Thinly sliced scallions or cilantro leaves, for serving

Instructions

1. Preheat the oven to 325°F and set a rack in the center.
2. In a large bowl, add the coriander, cumin, paprika, salt, pepper, cinnamon, cardamom, and cloves, and stir to combine. Add the ribs, and rub the seasoning evenly over them.
3. Wrap each rack tightly in aluminum foil, and place on a large, rimmed baking sheet. Roast until the meat is tender when poked with a knife, about 1½ hours.
4. Meanwhile, make the sauce: In a medium bowl, add the ketchup, harissa paste, honey, mustard, vinegar, and Worcestershire sauce. Whisk to combine, then set aside.
5. Unwrap the ribs, discarding the foil and any rendered fat. Preheat the broiler, line the baking sheet with a fresh sheet of foil, and place a wire rack on top. Set the ribs on the rack and broil, watching closely for burning, until browned and crispy, 5–10 minutes.
6. Remove the baking sheet, brush the ribs with a thin layer of the prepared sauce, then continue broiling until the tops are glazed and sticky, 1–3 minutes more.
7. Remove the racks from the oven, let cool slightly, then slice into individual ribs. Transfer to a platter, top with scallions or cilantro, and serve hot, with extra sauce for dipping.