Preheat oven to 250ºC /475ºF.

Boil or steam spinach, drain well and chop in a blender.

Melt butter in a pan, add the flour and stir for 1 minute to make a roux.

Add the milk and stir until mixture boils and thickens.

Quickly stir in the egg yolks and spinach and transfer to a large bowl.

Beat the egg whites until soft peaks form, and then fold them into the spinach mixture.

Pour the mixture into a greaseproof paper lined swiss roll tine ( 25cm x 30 cm)

Bake for 12-15minutes or until puffed and golden. Remove from oven.

Turn onto a rack covered with a tea towel.

Remove paper, and spread evenly with the filling.

Holding the tea towel with both hands , gently roll the roulade.

FILLING

Combine drained and mashed tuna or salmon, mayonnaise and shallots.