Salmon skin side down, until it lets go

I don’t have a proper market with iced counters where the fish lies whole, with clear eyes and red gills. There is a shop near home, a tray and a label. So I look more carefully than my grandmother did when she bought from her regular stallholder. Red fish, salmon or trout, is what I buy most often, because the children eat it without arguing and it cooks in minutes.

First the eyes, then the nose. A good salmon fillet shines like a wet stone, not like a grey rag. The flesh is even in colour, deep orange or pink, with the white lines of fat clean and bright, and no dry, pale corners or brown edges. When I press the packet gently, the flesh should feel firm, not soft and falling apart under the film. If the pack is blown up like a balloon, I don’t even start the argument; it stays on the shelf. At home, when I open it, it should smell of the sea and cucumber, not of ammonia or anything sour.

I read the label too. Fresh fish has a “use by” date, and that date is about safety, so I cook it on or before that day and I don’t stretch it. Frozen salmon I am not afraid of at all: frozen quickly, it is an honest option away from the sea. I only check there is no thick coat of ice and no dry, yellowish patches, which are freezer burn.

At home the fish doesn’t wait in the shop tray on the worktop. It goes straight into the fridge, on the bottom shelf in a covered dish, so no juice can drip onto anything else. Frozen fillets I thaw overnight in the fridge on a plate, never under a hot tap or on the side. Raw fish has its own board, and I wash the board, the knife and my hands in hot soapy water once it is in the pan.

The cooking itself is quick, and that is the moment worth watching closely. I take the fillets out of the fridge about ten minutes before, while the pan heats, and pat them very dry with kitchen paper, especially the skin. Dry skin goes crisp; wet skin steams and sticks. A tablespoon of oil goes into a heavy frying pan over a medium-high heat. When the oil shimmers, the fillets go in skin side down, away from me, and I press each one gently with a fish slice for the first few seconds so the skin stays flat.

Then I leave it alone. That is the hardest part. For four to five minutes I don’t move it, while I watch the colour change from the bottom up: the raw, glossy orange turns pale and opaque, climbing up the side of the fillet. When about two-thirds of the fillet has turned and the skin lets go of the pan by itself, I turn it over and lower the heat a little, add a knob of butter and let it melt and foam. Then I tilt the pan and, for one or two minutes, keep spooning the foaming butter over the top of the fillet; it carries the heat over the flesh and smells nutty. If the butter starts to turn dark brown, the heat is too high. A fillet about two and a half centimetres thick usually needs six or seven minutes in all. It is ready when the flesh is opaque all the way through and flakes easily when I press it with a fork; the Food Standards Agency advice is to cook fish until it is steaming hot right through.

Salt at the end, with lemon and dill. That is all. I don’t mask doubtful fish with garlic. If a fillet already bothers me when I open it, it goes in the bin, and supper is chicken or eggs. With crisp-skinned salmon I serve boiled new potatoes and something green, cucumber or peas, nothing that argues with the fish.

Leftover cooked salmon I cool, cover and put in the fridge within a couple of hours, and we eat it the next day, cold in a salad or flaked into scrambled eggs.

Fresh fish in my house doesn’t live “for later”. Either into the pan today, or honestly something else. What do you look at first when you buy salmon: the colour, the date, or the smell?