1 1/4 pints (750ml) milk
1 slice of onion
2-3 sprigs of fresh parsley
1 bay leaf
a few black peppercorns
3 oz (85g) butter
2 1/2 oz (70g) plain flour
1/2 teaspoon grated lemon zest
1 egg, beaten to mix
salt and pepper
5 oz (145g) water biscuits, coarsely crushed
1 1/2 lb (700g) skinless white fish fillets, finely diced
8oz (225g) skinless smoked haddock or whiting fillet, cut into strips
2. Bring the milk to the boil with the onion, herbs and peppercorns. off the heat, let stand 20 minutes to infuse. Melt 2 1/2 oz (70g) of the butter, stir in the flour, then strain in the milk. Bring to the boil, whisking constantly, then simmer until thickened. 3. Remove the pan from the heat. Add the lemon zest and egg and mix well. Season with salt and pepper.
4. Scatter about one- third of the biscuit crumbs over the bottom of a butterd baking dish. Cover with a layer of half the diced fish. Spoon half the sauce over the fish and arrange the strips of smoked fish on top. Repeat the layer of crumbs, fish and sauce.
5. Scatter the remaining biscuit crumbs over the surface. dot the top with the remaining butter.
6. Bake for about 35 minutes or until bubbling round the edges and lightly browned on top. Serve hot.