Method
Pre–heat the oven to 200ºC (180ºC fan ove
n). Place butter and mushrooms in a saucepan and fry gently. Add flour and milk and place over a medium heat. Whisk constantly until the sauce thickens. Add both cheeses.
Separate the eggs and whisk the egg whites until thick.
Beat the egg yolks into the sauce with the smoked salmon, parsley and crème fraîche. Gently fold in the egg whites.
Spoon into prepared dishes. Bake in a tin half–filled with cold water for 20–25 minutes until well risen and golden.
Serve on a bed of spinach.