MAKES ABOUT 30 CROQUETTES
At the end of an isolated mountain valley in Bierzo, in the far northwest corner of Castilla y León, is the tiny village of San Facundo. From the steep hills rising behind it comes a stream that passes through the center of town. The local park and swimming hole doubles as a trout fishing run. A small creek that feeds into it passes directly under a restaurant called Las Hoyas and is siphoned off into a private vivero (nursery) for trout and eel, two specialties of the house and its young chef, José Manuel Arias. When I ordered the eel, José brought me a plate of these croquetas and then went out to the vivero to net the rest of my lunch.
When frying various batches in a skillet, breadcrumbs gather in the bottom and burn. These tend to stick to the new batch and leave a bitter taste. After two batches, I very carefully filter the oil into a new skillet, bring it back to the correct temperature, and then continue frying.
1. In a large skillet or sauté pan, heat 1 tablespoon of the extra-virgin olive oil over medium-high heat until very hot. Season the trout with salt and pepper and lay them in the pan. Fry, turning once, until just opaque throughout (test for doneness along the backbone with the tip of a knife), about 4 minutes on each side. Transfer them to absorbent paper towels to drain off excess oil.
2. Once the trout are cool enough to handle, carefully and patiently remove all of the meat, discarding the skin and bones.
3. In a clean skillet or sauté pan, heat the remaining 6 tablespoons olive oil over medium heat and add the onion. Cook until soft and transparent but not yet browned, about 12 minutes. Add the jamón and garlic and cook, stirring frequently, for 2 minutes.
4. Meanwhile, in a medium saucepan, bring the milk to a simmer; season with salt, pepper, and nutmeg. Reduce the heat, cover the pan, and keep hot.
5. Sift the flour into the skillet over the onion and jamón, reduce the heat to medium-low, and cook, stirring constantly for about 2 minutes. It should be a compact and just-moist ball. Spread out the ball in the pan and begin slowly stirring in the hot milk until the mixture is creamy and not too sticky when touched, about 5 minutes. Reduce the heat to low and fold in the trout and the hard-boiled egg. Cook, gently stirring, for 2 minutes. The mixture should be spongy and can be touched without sticking to your finger.
6. Transfer the mixture to a large bowl to cool. Once cool, cover with plastic wrap and refrigerate for several hours until chilled. (This will make forming the croquettes easier.)
7. On a flat work surface dusted with flour, form croquettes into 2- or 2½>-inch-/5- to 6.25-cm-long cylinders about 1 inch/2.5 cm in diameter. Lightly roll in flour.
8. Break the eggs in a bowl and thoroughly whisk. Place the breadcrumbs in a second bowl.
9. Dip the croquettes in the egg, and roll in breadcrumbs to completely cover.
10. In a skillet or sauté pan, heat at least ¾ inch/2 cm of sunflower oil over medium-high heat. Reduce the heat to medium-low.
11. Working in small batches that don’t crowd the pan, fry the croquettes, turning frequently, until they are golden on the outside and hot and creamy at the center, 1 to 2 minutes. Gently transfer them to absorbent paper towels to drain off excess oil. Serve hot.