First you have to filet your fish. This is not one of the nicest jobs but – as the fish gets only cooked in lemon juice – it is better you do it yourself in your clean kitchen. Don’t get your fish chopped in the market where hygienic conditions tend to be a bit rough. To make filets you need a really sharp, big knife and a big size cutting board.
Start with chopping off the head and all fins. After this slice open the belly and remove all the inners. Then cut along the spine. Open up this initial cut by carving along the big bones, severing the filets. Finally remove the skin from the filets. Wash them well under running water and pat the filets dry with kitchen towels. Then cut the filets in slices around one centimeter thick.
Now it is time to squeeze the lemons. As they vary in size, don’t stick with the number. 15 is only a rough guide. If you find only small lemons, use more. Squeeze the lemons as you see fit. I don’t like a citrus press, I just take a small sieve on top of a jar, I halve the lemons and I squeeze away over the sieve. The seeds end up in the sieve and the lemon juice drips down. Of course you can buy lemon juice ready made in a glass bottle and use this for cooking the fish. However I prefer to make the effort and be sure of the freshness of the juice.
Now take a deep dish and arrange the fish slices on the bottom. Salt and pepper them according to your taste. Slice the chilies open, remove the seeds and cut them into fine stripes. Sprinkle the chilies over the fish. Then cover everything with lemon juice. It is very important that the fish is completely covered as the acid in the juice does the cooking.
Place the dish in the fridge and marinate the fish for at least 6 hours. During this time the acid in the lemon juice is slowly simmering the fish, changing its color from grey to white.
Once the cooking time, or better marinating time, is over, drain the lemon juice and pour the olive oil in a thin stream all over the fish. There is no further cooking required, Serve immediately with some vegetables or a salad on the side. Garlic bread goes very nicely with this fish.
Be careful. This dish cannot be kept for more than a day. Fish marinated in lemon juice has to be eaten as freshly as possible.