For the salmon and leeks cream:
Leeks and salmon cream preparation :Mix 1 1/2 cup of sliced leeks with Swiss cheese and smoked salmon slices. Salt and pepper. Add a bit of lemon juice.Once the roll is cooked, roll within cooking paper and lightly cool down. Unroll paper and spread leeks cream. Roll up again. Maintain roll tight. and refrigerate for 12 to 14 hours.