Preparation time 30 minutes
Cooking time as desired

Peel and cut potatoes into thin slices. Blanch in salted water, then drain the slices, pat dry, add oil and flavour with parsley and marjoram, salt and a little pepper.
Cut the asparagus into small pieces and toss in pan with speck and a drop of oil. Grate half the cheese and cut the remainder into sticks.
Open the dough on the work surface and cut some strips for decoration.
On one side of the pastry spread the slices of potato mixed with 2 tablespoons of grated Fiore Sardo, then add a layer of asparagus, grated and stick-cut cheese.
Roll up strudel, sealing edges well, then decorate with a puff pastry lattice.
Transfer the preparation on the plate protected with parchment paper, brush the crust with 1 egg yolk beaten with 3 tablespoons of milk and bake at 200°C for 20 minutes, then continue cooking for 10 minutes with a convection oven and heat only from below.