Mix all ingredients for the filling with a hand blender.
Roll out the puff pastry, spread the filling and leave an edge of approx. 3 cm. Cover with ham and cheese and roll up carefully. Fold in the edges and brush the rolled-up strudel with 1 whisked egg.
Bake in the oven at approx. 190 degrees for 40 minutes, then leave to rest for 10 minutes.