for the dough ,wash the spinach,blend to a pulp ,drain very thouroughly. Combine flour,egg ,oil,salt and spinach.Add 60 ml lukewarm (tepid) and mix until it forms a strong dough.Knead for at least ten minutes after that until dough becomes elastic.Cover with a bowl or wrap and let rest for 1/2 hour at room temperatur.

for the filling cut the fish into cubes. mix with icecubes and crème fraîche pulse in blender (so that the fish does not get to warm) until very smooth.Add one egg and the yolk of the other, set aside the eggwhite. Season this mixture with rind and some juice of the lemon ,as well as salt and pepper

Divide dough into two halves ,roll out onto floured worksurface to about the thickness of a knife. Add about a teaspoon of salmonfilling every 5cm (2inch) in a row. Use the reserved eggwhite to brush the dough inbetween the gaps. Cover with the second equally sized rolled out dough and press together firmly around the filling. Cut out the ravioli cushion with knife or a doughwheel .

Boil some salted water,then bring to simmer gently. Cook ravioli for about 6 to 8 minutes.

In the meantime melt the butter until it starts to bubble, flashfry the sage leaf .Use a slotted spoon to take ravioli out of pan and drain . Add to the butter stir gently and again season wih salt and pepper. Serve immediately.