Pre-heat the grill to medium-high. (See notes for stovetop)
Make a paste with the olive oil, ras el hanout, salt, garlic and lemon zest, mixing together in a medium bowl.
Add the chicken, and toss to coat all sides well. You could do this a day before and refrigerate.
Grill the thighs over medium-high heat, getting good grill marks on both sides. Move to a cooler side of grill, cover, and grill until cooked through (to 170 F), or place in a warm 350F oven to finish.
Right before serving, Squeeze with lemon and sprinkle with fresh herbs (mint and/or parsley) or make the flavorful Preserved Lemon Gremolata, and spoon over top.