In a medium bowl, combine the lemon zest, lemon juice, garlic, honey, dried oregano, harissa paste, olive oil, Kosher salt, and freshly ground black pepper.
Place the lamb and the harissa marinade into a large Ziplock bag. Close the bag and flip a few times to coat the lamb. Refrigerate and let marinate for at least two hours or up to overnight (the longer the better).
When ready to grill, remove the lamb from the refrigerator and let come to room temperature.
Outdoor Grill Instructions: Preheat a gas grill over medium-high heat. (TIP: I make sure my grill is non-stick by rubbing an oil-soaked towel on the grates). Lift lamb from the marinade and place on the grill. Cook the rib chops for 3-4 minutes per side for medium-rare and the loin chops 4-5 minutes per side for medium-rare. Set aside to rest for 5 minutes, tented with foil. (TIP: If lamb is not at room temperature before grilling, it won’t be medium-rare.)
Grill Pan Instructions: Preheat a grill pan, letting it get nice and hot, over medium heat. Lift lamb from the marinade and cook the rib chops on the grill pan for 2-3 minutes per side for medium-rare and the loin chops 3-4 minutes per side for medium-rare. Set aside to rest for 5, tented with foil. (TIP: If lamb is not at room temperature before grilling, it won’t be medium-rare.)
Serve on a platter with the Herby Pistachio Sauce and Tzatziki on the side, if desired.