Season the chicken breast with salt, pepper and cayenne pepper and fry on both sides in a pan in hot clarified butter.
Now place in a buttered baking dish and cover.
In the same pan, put the onion cut into rings and sauté well so that they get color.
Pour the finished onion over the chicken breast. Mix the cream and créme fraíche together, season well and pour over the whole thing. Preheat the oven to 180 ° and bake for 20-25 minutes.