Preheat your oven to 350 degrees, season the chicken with the salt and pepper.
Heat up the olive oil in a cast iron or oven safe skillet. Once heated, place your chicken pieces in a single layer in your skillet and sear until golden brown, about 5 minutes.
Add in the crushed garlic cloves and continue to cook until garlic becomes fragrant. Remove the chicken and garlic from the skillet.
Add the onion and shallot to the skillet and stir until the onions and shallots have softened, about 3 minutes.
Place your chicken pieces and garlic back in the pan in a single layer and sprinkle the thyme leaves on top of the chicken. Arrange the olives between the chicken pieces and top with the sprigs of thyme.
Bake for 45 minutes or until the chicken reaches the internal temperature of 165 degrees. Remove from the oven and serve.