Roll out the puff pastry into a thin rectangle on a floured surface and cut in half. Brush one half with water and sprinkle with the chopped herbs. Place the second half on top and roll out again. Place the puff pastry on a baking sheet lined with parchment paper, sprinkle with coarse sea salt and sesame seeds.
Place an oven rack on top and bake in a heated oven at 210 °C for about 20 minutes.
Cut the puff pastry while still warm, cool.
Marinate the leaf salad with pumpkin seed oil, apple balsamic vinegar and salt, place on the puff pastry slices and arrange the raw ham on top. Sprinkle with the mountain cheese and garnish with fresh chervil.
Our tip: As an alternative to fresh herbs, you can also use frozen ones – these also stand out for their fresh taste!