Cut the chicken into 16 pieces. Heat the butter and olive oil in a large flameproof casserole. When the butter is melted, raise the heat, then put in the chicken pieces and sauté gently, turning them, until they are golden all over (about 15 minutes). Season with salt and pepper.

Heat the broth to the boiling point in a saucepan.

Meanwhile, sprinkle the chicken with the flour and stir it thoroughly with a wooden spoon for 1 minute. Immediately pour in the hot broth, stirring thoroughly to prevent lumps from forming, then add the bay leaf and the thyme to the casserole and simmer slowly for 20 minutes, stirring every so often. Remove the bay leaf from the casserole and add the olives. Taste for salt and pepper and simmer for about 10 minutes more.

Remove the casserole from the heat and transfer its contents to a serving dish. Sprinkle over the parsley and serve hot.