Ham and Leek Croquetas

Equipment: Line a baking tray with baking paper.

Heat the butter in a medium saucepan. Add the leek, garlic and a pinch of salt. Cover and cook for 10 minutes until very soft, stirring often. Add the prosciutto and cook for 1 minute.

Stir in the flour and cook for 1 minute. Stir in half the milk to make a thick paste, then stir in the rest. Season generously and cook over a low heat for 3 minutes, stirring constantly. The mixture will be very thick with a silky sheen and should be pulling away from the sides of the saucepan. Stir in the cheese and nutmeg. Transfer to a shallow dish and press a piece of plastic wrap down onto the surface to prevent a skin forming. Cool then chill for several hours or overnight until very firm. 

To assemble and cook: Put the flour, eggs and breadcrumbs into three separate bowls and season each. With lightly floured hands, roll spoonfuls of the cold leek mixture into 4cm-long cylinders. Roll in flour, then egg, then breadcrumbs, making sure they are well coated. Place on a lined tray and chill for 2½ hours until very firm.     

Heat 4cm of oil in a deep sauté pan or wok to 175°C on a kitchen thermometer, or until a piece of bread turns golden in 30 seconds. Cook the croquetas in batches for about 3 minutes, or until golden. Don’t cook them too fast or the centres will still be cold. Drain on kitchen towels, then keep warm in a low oven until they are all cooked. 

Cook’s note: Serve with a bowl of mayonnaise mixed with crushed garlic and smoked paprika for dipping.