Separate chestnuts from the shell, boil in salted water until soft, strain through a sieve. Season the puree with finely crushed pepper, jam and new spices. Separate the savoy cabbage leaves from the stem, boil in salted water for two minutes, cool immediately when ice cold. Cut the venison fillet into small pieces (remove sinews and skin), brown it in hot butter, season with salt, pepper and new spices.
Defrost the pastry sheets, stack them on top of each other, roll them out to the thickness of a knife and cover them with the drained savoy cabbage leaves. Spread the chestnut farce on top. Place the venison fillet in the middle. Fold the dough over it and close it neatly around the edges. Place on a baking sheet with the seam facing down.
Brush the package with egg. Bake in a 180 °C oven for about 20 minutes.
To serve, cut open and drizzle with a tiny bit of gravy.