Cut the fillet into 2 equal portions (make sure it's skinned and deboned). Mix the cheese, butter and lemon juice together, then spread over one fillet. Place the other fillet on top so the cheese mix is sandwiched between them.
Roll out the pastry to about a quarter inch thickness, making sure it's big enough to wrap the fillets with some overlap. Separate all the chicory leaves and lay a single layer on the pastry where the salmon will go. Sprinkle with salt and pepper and lay the salmon on the chicory. Cover the fillets with the rest of the chicory leaves and the wrap with the pastry.
Glaze the pastry with egg wash and bake for 40 minutes in a preheated oven at 220 degrees Centigrade.
Serve with new potatoes, brocolli and Hollandaise sauce.