- Prepare marinade by mixing olive oil, minced garlic, chopped rosemary, thyme leaves, salt, and pepper in a bowl. 
- Coat Costco lamb chops with the marinade, then refrigerate for a minimum of one hour. 
- Preheat the grill to medium-high heat. 
- Remove excess marinade from the lamb chops before placing them on the grill. 
- Grill the lamb chops for about 3-4 minutes on each side for a medium-rare result. 
- Serve the Costco lamb chops.