Salmon fillets, salt and pepper, drizzle with lemon juice and put in the fridge!
Blanch the spinach leaves in salted water, rinse in cold water and place on a dry cloth.
Roast the leek well in 1 tablespoon butter (do not let it brown), salt and pepper!
Line the baking sheet with parchment paper.
Place a strudel sheet on a damp cloth and brush with melted butter. Place a second strudel sheet on top and also brush with butter. Halve the strudel leaves crosswise. Cover the top of each half of the dough with two spinach leaves, then spread the salmon fillet on top and then the leek on top of the salmon. Fold in the edge of the dough on the right and left and then roll up the fillet piece, possibly with the help of the cloth! Now brush the strudel packet with butter and place on the tray.
Bake in an oven preheated to 190 ° C for about 20 to 25 minutes. The dough should be slightly brown!
Now for the dip: stir well the sour cream, dill, salt and pepper, done!