Preheat oven to 400F, 200C, Gas Mark 6. Roll out the pastry and use to line a 9 inch (23cm) flan dish. Bake blind for 15-20 minutes. Place the fish and courgettes in the bottom of the flan case and sprinkle over the cheese. Beat the eggs thoroughly, blend in the milk, Dill Weed and Nutmeg. Pour over the fish and return to the oven for 30-35 minutes or until lightly golden and firm to the touch. Serve hot or cold.