Preparation

Coarsely chop the garlic, sprinkle 1⁄2 tsp. of the salt over it, and continue chopping until the garlic is a paste. Add it to a small bowl, and stir in the remaining salt, the pepper, and, if using, herbes de Provence and fennel seed. Rub the seasoning mixture all over the chicken and under the skin. (This can be done up to 1 day before cooking the chicken.) Bring to room temperature before cooking.

Preheat the oven to 375°F. Tightly wrap a brick in 2 layers of aluminum foil, and place in the oven to heat up, about 30 minutes. Heat a large, heavy skillet (preferably cast iron) over medium heat, and add the olive oil. When the oil is shimmering, place the chicken in the skillet, skin-side down. Be sure to give each chicken thigh some space around it. Place the heated brick on top of the chicken, and cook until the skin is sizzling and golden brown, about 7 minutes, moving it as needed to give each piece of chicken an equal amount of pressure. Turn the chicken thighs, and transfer the pan to the oven to finish cooking, about 5 minutes.