In a frying pan, cook the shallots and mushrooms in butter.
Add the white wine and reduce until almost dry.
Add the cubed cheese, the smoked salmon and warm slightly.
Add the lemon.
Brush 1⁄2 sheet of filo pastry with melted butter.
Spread a bit of the preparation at the beginning of the sheet and roll like a cigar.
Join the two ends of the cigar together and paste with a bit of butter.
In a preheated 350ºF oven, bake the corollas brushed with butter for fifteen minutes.
Remove from the oven and let cool a few minutes.
Put the heated sauerkraut in the centre of the corollas.