Steamed fish, spring onion sauce

A large (28cm), shallow, cast iron and enamelled casserole dish is a great accessory. You can fry in it, roast in it (I used it recently for a shoulder of lamb) make stews in it, and use it for large gratins; because of its size, you can easily transfer it from the stove top to the oven. Because of its weight, you can keep things warm in it for a while. So, for example, I was able to drain off the sauce from my roast lamb, carve the lamb and put the pieces back in the casserole and cover them, finish the sauce, and then pour the sauce back over the lamb for serving. Had I felt it necessary, I could have warmed the carved lamb and sauce on the hob.

The dish will also contain large fish fillets, and keep them warm while you make a sauce.

2 fish fillets (I had smoked haddock)
1/3 pint of milk
A few peppercorns
A bay leaf
A scraping of nutmeg
Salt (smoked fish will already be salty)
18g unsalted butter
1dstsp flour
4 spring onions, chopped

Put the fish in a heavy dish or saucepan, and cover with the milk. Add the peppercorns, bay leaf, nutmeg, and salt (if using).

Cover the pan, and put it over a medium flame on the hob. Check to see when the milk starts simmering, and when it does turn down the flame to its lowest (with the pan still covered). The fish should be tender about five minutes after the milk simmers.

Meanwhile, make a roux: melt the butter in a small saucepan over a gentle heat, add the flour, and cook gently for a minute. The mixture should be the texture of loose sand. Add more butter or flour as necessary. Set aside.

Remove the fish to a chopping board or plate, strain the milk into a jug, return the fish to the pan or dish, and cover.

Put the pan with the roux back on the hob, above a medium heat. Stir in the milk from the jug, a little at a time, incorporating each portion before adding the next. After the second or third addition, throw in the spring onions, which will throw off liquid and thin the sauce. Keep adding milk until you have a sauce of a texture you like, adding more from a bottle (or carton) if necessary.

Serve the fish with the sauce poured on top.