Mushroom Strudel

Having lived for a couple of years in Vienna, strudel was known to me only as an excellent dessert, either filled with apples, pears or sour cherries, or with a paste of poppy seeds. The idea of making it savoury, with a mushroom filling, is perhaps not completely new in general terms, but it is for me, and here it is. To be lazy, 1 use bought filo pastry, but if you are a skilful maker of the original strudel pastry, feel free!