1. In a large, shallow dish, combine the 1/4 cup of olive oil with the thyme, minced garlic, rosemary and cumin. Add the lamb chops and turn to coat with the marinade. Refrigerate overnight.
2. Preheat the oven to 350°. Set the halved heads of garlic cut side up on a large sheet of foil and drizzle with oil. Wrap the garlic in the foil and roast for 1 hour, until tender.
3. Light a grill. Remove the chops from the marinade; discard the thyme and scrape off the garlic. Season the chops with salt and pepper and grill over moderate heat until lightly charred and medium-rare, 5 minutes per side. Serve the chops with the roasted garlic and White Bean Puree.