Clean and salt 1 large hen. Place ½ lb butter, root vegetables, and spices in a stewpan. When the butter begins to bubble, add the hen and stew, covered, until tender, turning it and adding a little water. When the hen is cooked, remove and cut into parts. Return the pieces to the pan, add 3 glasses bouillon, and cook for another ½ hour.
Meanwhile, fry 1 spoon flour in butter, dilute with the hen bouillon, and add a little vinegar or lemon juice and 1–2 pieces sugar. Bring the sauce to a boil, strain, and pour over the hen. Add prunes that have been boiled in water, covered, left to stand 1–1½ hours, and removed from the water with a slotted spoon. Bring everything to a boil once more.
Serve in a vol-au-vent. That is, bake a circle of dough with sides, using puff pastry or short pastry. Transfer the baked pastry shell onto a platter, arrange the hen with prunes on top, and pour on a little sauce. Serve the remainder of the sauce separately. To economize, make soup from the hen and serve the boiled flesh in the vol-au-vent.