2. Arrange the fish in a buttered baking pan. Sprinkle with salt and pepper.
3. Mix the breadcrumbs and walnuts in a food processor until the walnuts are finely chopped. Transfer to a medium size bowl and mix in the butter, horseradish and mustard. Stir in the parsley and cheese.
4. Gently press the crumb mixture onto the fillets and drizzle with olive oil.
5. Bake for 15 minutes and then put under broiler and brown the crust. (Do not burn)
Serve these with Lemon Dill Sauce poured over the top of each fillet.