In a small bowl, combine the lemon zest with the minced thyme, salt and pepper. Rub this mixture on the underside of the chicken thighs and over the skin. In a 9×13 baking dish, scatter the onion, garlic cloves, lemon slices, and thyme sprigs. Arrange the chicken thighs on top and bake for 35-45 minutes, until the internal temperature registers 165 degrees. If needed, turn on the broiler to brown and crisp the skin for a couple minutes. Use a wooden spoon or fork to mash the now softened garlic and lemons into the pan drippings. Discard the lemon rinds, but serve the saucy, lemony onions and garlic with the chicken, accompanied by rice or orzo and your favorite green vegetable.
