Ingredients :

• Chicken breasts — Get thick breasts if you can, not the thin, dry vacuum-packed ones. Cut them yourself into 4-5 cm chunks — you’ll have better control over size and even cooking.
• Fresh button mushrooms — Mushrooms must be fresh. Canned mushrooms will release a grey liquid that dilutes the whole sauce. Fresh ones cook down, release just enough moisture, and stay firm to the bite.
• Egg yolk + crème fraîche — This is the heart of the recipe. This liaison gives the sauce its velvety texture and that slightly pearly ivory-white hue. Don’t replace crème fraîche with light cream — the result isn’t the same.
• Grated nutmeg — A pinch, no more. Nutmeg is powerful and can overpower the rest if you overdo it. Grate it fresh if you have a whole nut — you can really taste the difference compared to canned powder.