In a cast iron casserole dish with a lid, brown the chicken breasts in a little oil and butter, starting with the skin side and seasoning them on both sides.
When they are golden on both sides, add a knob of butter, the thyme and the garlic. Stir constantly over high heat for 3 minutes before putting the lid on and allowing to finish cooking over low heat.
Meanwhile, fry the shallot in a pan with butter. Deglaze with the Madeira. Reduce by half before adding the chicken stock. Reduce the chicken stock by half before adding the veal stock and reducing the sauce to a light, coating consistency.
Heat the Isigny Sainte-Mère Crème & Foie Gras gently without cooking it.
Proceed with the presentation, checking that the chicken is cooked. Cover with the sauce. Serve the chicken lightly drizzled with Isigny Sainte-Mère Crème & Foie Gras.