Omelette Arnold Bennett

• 1 smoked haddock on the bone (about 1 lb)
• ½ pint milk

Trim tail and collar bones from the haddock and poach gently in half a pint each of milk and water, until the bones come away easily. Make a thick Béchamel sauce with the flour, half the butter and the cheese, using some of the liquid in which the fish has cooked. There should be about half a pint of thickish sauce. Bone the fish and put the flaked pieces into the sauce, reserving about three t