Saute the finely chopped onions in the butter and 2 tablespoons water. Add the sliced meat. Saute it as well and throw in the finely chopped mushrooms.
Pour on the wine and saute on low heat until the meat softens. Season with salt and black pepper. Whisk the yolks with the cream.
Pour them over the meat and immediately remove from the heat. Stir until the dish cools.