Peel the asparagus and cut into sections. Cook in a pan in butter over medium heat until al dente. Mix the asparagus sections and the diced ham with the creme fraîche, season.
Preheat the oven to 180 ° C convection (200 ° C top / bottom heat). Roll out the puff pastry, spread the filling on top, leaving the edges free. Brush the edges with egg, close the strudel and press the edges firmly with a fork.
Brush the strudel with egg. Bake for about 25 minutes, if necessary turn down the heat if the strudel gets too dark.