Have the grill preheated to medium-high heat.
In a small bowl combine the salt, cumin, paprika, and cayenne. Sprinkle half of the spice mixture over the chops and let sit at room temperature for 30 minutes.
For the Charmoula: In a food processor or blender, add the remaining spice mixture, the onions, parsley, cilantro, garlic, olive oil, lemon zest and juice. Blend until smooth and season with salt and pepper, to taste. Set aside.
Brush the chops with olive oil and put on the grill. Grill until the lamb is medium-rare, about 4 to 6 minutes on each side. Transfer the chops to a serving platter and serve with the charmoula.