Caldillo de congrio — Chilean conger eel soup with potatoes, white wine and cilantro

1 ✓

Make the stock from the head and backbone

Cut the gills out of the head with a knife or kitchen scissors and rinse the head and backbone under cold running water until no blood remains: gills and blood make the stock bitter and cloudy. Put them in a pot with the 1.75 litres of cold water, one halved onion, one carrot in chunks, the bay leaf, a few peppercorns and the cilantro stems. Bring to the boil over medium heat and skim off the grey foam that rises with a spoon. Lower the heat so it barely bubbles and cook for 30 minutes uncovered: fish gives up its flavour quickly and, cooked much longer or boiled hard, the stock turns bitter and cloudy. Strain it through a fine sieve; you should have about 1.5 litres (top up with water if short).

2 ✓

Marinate the conger steaks

While the stock cooks, pat the steaks dry with kitchen paper and lay them in a dish. Season them with 1 teaspoon of salt, ground pepper and the juice of half the lemon, turn them so they are coated on all sides and keep them covered in the fridge until it is time to cook them, 30 to 45 minutes. The salt seasons the flesh all the way through and firms it, which helps the steaks hold together in the pot. Do not leave them for hours: the lemon's acid starts to cook the surface and turns it soft.

3 ✓

Sauté the vegetables and add the wine

When the stock has about 20 minutes to go, heat the oil over medium heat in a wide pot that will later hold the steaks in a single layer. Add the other onion, thinly sliced, the carrot rounds, the red pepper and a pinch of salt, and cook for 8-10 minutes, stirring now and then, until the onion is soft and translucent but not browned. Add the garlic, ají de color and oregano and stir for 1 minute: the paprika burns quickly and turns bitter, so keep an eye on it. Add the grated tomato and cook for 5 minutes, until it breaks down. Pour in the wine and let it boil for 3-4 minutes, until reduced by half and no longer smelling of alcohol.

4 ✓

Cook the potatoes in the stock

Pour the strained stock over the sofrito, add the potatoes and the second teaspoon of salt and bring to the boil. Lower the heat to medium-low and cook for 12-15 minutes, until the tip of a knife goes into the potatoes with slight resistance at the centre: they will finish cooking with the fish. The potatoes go in first because they take longer than the fish; if both go in together, the congrio overcooks while the potatoes are still hard.

5 ✓

Simmer the conger gently

Drain the steaks and arrange them on top of the potatoes in a single layer, pressing them down gently so the broth covers them; if any stick out, baste them with a ladle. Adjust the heat so the broth barely bubbles and cook for 8-10 minutes without stirring: a spoon breaks the steaks, so if needed, move the pot by its handles. The congrio is ready when the flesh turns from translucent to opaque white right to the centre, flakes when pressed with a fork and comes away easily from the central bone; with a thermometer, 63 °C in the centre of the thickest steak. Turn off the heat at that point, because the hot broth keeps cooking it.

6 ✓

Finish with cream and cilantro, and serve

If using cream, mix it in a bowl with a ladle of the hot broth to temper it and pour it around the steaks with the heat already off; swirl the pot gently. The heat of the broth is enough to warm it and, since it does not boil, it will not curdle with the acidity of the wine and tomato. Taste and adjust the salt. Serve in deep bowls, one or two steaks per person with potatoes and vegetables, cover with piping-hot broth and sprinkle with the chopped cilantro. Put the lemon wedges and some bread on the side for the broth.