Take the dough out of the refrigerator 10 minutes before processing.
Briefly steam the chopped onion and garlic in a little butter, leave to cool. Mix all ingredients for the filling well and form into 2 rolls, roll them tightly in the puff pastry. Chill for about 30 minutes.
Then halve the rolls lengthways, twist both halves into a cord so that the side of the dough is always at the bottom. Brush visible pieces of dough with egg yolk.
Bake at 200 degrees for about 40 minutes until golden.