Place puff pastry sheets next to each other on the worktop to defrost. Roughly grate the cheese. Season quark with salt and pepper. Wash basil, shake dry, pluck leaves from the stalks and chop coarsely.
Spread and spread the quark on the puff pastry sheets, cover with bresaola, sprinkle with basil and cheese. Roll up the plates from the short side and cut each into approx. 8 slices. Spread the slices on 2 baking trays lined with baking paper.
Whisk the egg yolk and milk and spread a thin layer on the rolls. Bake in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: see manufacturer) one after the other for approx. 15 minutes.