Peel and quarter 2 onions. Wash the meat, dab dry. Season with salt and pepper. Put the onions on a baking tray coated with 1 tablespoon of oil. Pre-bake in a preheated oven (electric: 200 °C/ gas: level 3) for about 30 minutes. Take out and let cool down for about 30 minutes
Deglaze the meat with broth, loosen and sieve. Set the stock aside
Defrost the puff pastry. Peel 2 onions and chop finely. Clean the mushrooms, wash if necessary and chop very finely. Heat 1 tablespoon of oil in a large pan. Fry the onions in it. Add the mushrooms and stir-fry for approx. 10 minutes until all the liquid has evaporated
Wash the herbs, dab dry and chop finely. Mix with mushroom mass, egg and breadcrumbs. Season with salt and pepper. Place 2 puff pastry slices on top of each other and roll out to the size of the roast. Spread about 1 cm thick with the mushroom mixture. Place the meat on top and spread with the rest of the mushroom mixture.
Place 2 puff pastry slices on top of each other and also roll out to the size of the roast. Roll over this pastry sheet with a grid roller. Pull the grids apart and place them over the roast. Press down firmly at the edges. Stir egg yolk and 1 tablespoon of water until smooth. Spread the dough with it
Place the roast on a baking tray lined with baking paper. Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) on the lower rack for approx. 45 minutes
Clean, wash and halve the pointed cabbage. Remove stalk. Cut cabbage into strips. Peel, wash and slice carrots. Peel the remaining onion and chop finely. Heat the fat. Sauté onion in it. Steam pointed cabbage and carrots briefly. Pour on 1/8 litre of water, cover and stew for about 10 minutes. Season with salt and nutmeg
Bring the stock to the boil and let it boil down for about 5 minutes. Stir starch and 2 tablespoons of water until smooth. Bind the stock with it. Season sauce with salt and pepper. Serve everything