Place the puff pastry slices next to each other and defrost. Peel the asparagus, cut off the woody ends and cut into approx. 4 cm long pieces. Cook the asparagus in boiling salted water for about 3 minutes, remove and drain.
Cut the puff pastry slices in half to create squares of approx. 12 x 12 cm. Grease the hollows of a muffin tray (12 hollows) and dust with flour. Line with puff pastry.
Add ham, cheese and asparagus. Mix eggs, sour cream and yoghurt, season with salt and pepper and pour into the moulds. Lightly twist in any protruding puff pastry tips. In a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see
manufacturer) bake for about 20 minutes. Let the muffin tray cool down on a cake rack for about 30 minutes, carefully lift the muffins out of the trays and serve.