Thaw the puff pastry and roll out into a large rectangle.
Cut the onion into fine cubes, cut the paprika into fine strips, cut the white cabbage into fine strips. Fry the onion and minced meat, then add the cabbage first and fry with it. Add a pinch of sugar and let it caramelize a little. Add paprika and steam with it. Finally, add the mushrooms and deglaze the whole thing with a good dash of soy sauce and season with the spices. Let cool down well!
When the mixture has cooled down, distribute it on the dough rectangle. Then shape into a roulade. Place the roulade with the seam facing down on a baking sheet lined with baking paper. Then brush with egg yolk and bake for about 30 - 35 minutes at 200 ° C top / bottom heat.