Melt butter in a saucepan, saute spring onion or onion until soft, approximately 2-3 minutes.

Add flour & cook 1-2 minutes until frothy.

Gradually stir in milk & heat until boiling, then add basil & fish.

Simmer 3-4 minutes until sauce is smooth & thickened.  Season to taste with salt.

Stir in mussel meats, egg, lemon juice, nutmeg & pepper to taste.  Allow to cool.

Cut sheets of pastry into widthwise strips 4cm wide.  Brush 1 strip with melted butter.  Place a teaspoonful of filling on bottom left hand corner of strip.  Fold bottom right hand corner over filling to form a triangle.  Then fold triangle up, then to the right & continue folding, keeping triangle shape with each fold.

Place triangle, seam side down, on a greased tray.  Repeat with remaining strips & filling.

Brush completed triangles with melted butter & bake at 200°C392F until golden brown, approximately 10-15 minutes.

Serve warm.