Preheat the oven to 180°C (top/bottom heat). Roll out the puff pastry on a baking tray lined with baking paper. Whisk together the egg yolk, milk, salt and pepper and use it to brush the edge (approx. 3 cm wide) of the puff pastry.

Chop the pistachios and mix with the sesame seeds. Spread the mixture over the edge of the puff pastry. Bake the puff pastry for 15 minutes until golden brown.

Mix cream cheese and sour cream. Wash and dry the vegetables. Divide the spring onions into thin rings. Cut the radishes into narrow slices.

Allow the finished baked puff pastry to cool briefly. Then spread cream cheese inside the pistachio edge. Top with spring onions, radishes, smoked salmon and lamb's lettuce.