Heat oil in a pan and sauté the shallots. Add mushrooms and roast until there is no more liquid in the pan. Season with chopped parsley, salt and pepper.
Take the puff pastry out of the fridge approx. 10 minutes before processing and preheat the oven to 220° C. Season the loin roast with salt and pepper and fry it in hot oil on all sides. Lift meat out of the pan and let it cool down completely.
Unroll the puff pastry, place cabbage leaves on the pastry, spread the onion/champignon mixture evenly on the pastry, place the lungfish on top and roll up tightly. Close the ends well, brush with whisked egg and decorate with any leftover pastry.
Bake hot for approx. 10 minutes, reduce temperature to 170° C and bake for approx. 20 - 30 minutes. Then cover with warm aluminium foil and let rest for 10 minutes.
For the sauce: Sauté the shallot in the roast of the lungfish. Deglaze with Madeira, pour in beef stock and reduce. Finally, stir in ice-cold butter and do not bring to the boil again!