Creamy Roasted Garlic Penne

Trim the top thirds of garlic heads. Set on parchment-lined foil, drizzle with olive oil, top with thyme, and wrap. Roast at 400 degrees for 1 hour. Cook penne, reserving 3/4 cup pasta water. Squeeze garlic out of skins and heat in a skillet with pasta water and cheese, whisking until thick and creamy. Stir in cream, and penne. Season, and top with greens.