1. Melt 40 g of butter in the pan.
2. As soon as it foams, sear the escalopes on both sides without letting them brown. Set aside and keep warm.
3. Pour in the white wine, bring to a boil, add the mustard and tarragon as soon as it is diluted, return the escalopes to low heat, season with salt and pepper, add the mushrooms sliced after washing them with lemon water, and the cream.
4. Let cook for 15 to 20 minutes.
5. When serving, place the escalopes on a heated serving dish.
6. Dilute the egg yolks with a few spoonfuls of sauce and, off the heat, add them to the very hot sauce, stir. If necessary, reheat but do not let it boil. Pour the sauce over the escalopes.