Fillet the eels and cut into 8 cm (3 in) thick slices; blanch these slices in salted water, refresh them and drain well. Season with a little salt, pepper, grated nutmeg and chopped parsley then arrange them in layers in a deep pie-dish alternating with layers of seasoned, sliced hard-boiled eggs.
Moisten with 2 dl (7 fl ozor ⅞ U.S. cup) white wine, add 25 g (1 oz) butter and cover with a layer of puff paste. Eggwash the surface and decorate by scoring with the point of a small knife. Make an opening in the centre to allow the steam to escape and cook in a moderate oven for 1½ hours.
Just before serving, pour 2 dl (7 fl ozor ⅞ U.S. cup) Sauce Demi-glace flavoured with fish essence through the hole.