Cover the crepes or pancakes with the pickled salmon slices. Mix the smoked trout with crème fraiche and dill in a blender. Season to taste with salt and freshly ground pepper. Spread on the pancakes topped with salmon and roll up. Wrap in foil and place in the freezer.
Take out of the refrigerator two to three hours before serving and cut into slices.
Best served on cucumber slices with lemon vinaigrette.