Steps

Combine smoked salmon, heavy cream, cream cheese, mascarpone, and lemon juice in a food processor.  Blend until smooth, scraping down the sides as needed. Fold in the chopped dill. Reserve until needed.

Melt butter in a small sauce pan along with milk and water. Temper in the eggs and then add wet ingredients to dry using a hand blender.  Strain through small holed china cap. 3. Make crepes using standard method.

Lay out crepe on work surface. With an offset spatula, spread an even layer of mousse. Leave about ½ inch of clean surface around the edges.  Tightly roll up the crepe into a spiral. Wrap tightly with plastic and place in cooler for at least one hour.  When needed remove plastic film and slice into ½ inch sections.