For the filling
100g ham, finely shredded
A splash of olive oil
A knob of butter
½ small leek, very finely shredded
60g plain flour
400ml whole milk
Nutmeg, to grate
A pinch of freshly ground black pepper
50g manchego or other hard cheese, finely grated
For the coating
2 large free-range eggs, beaten
Vegetable oil, to fry
Heat the oil and butter in a heavy bottomed saucepan over a medium heat until gently foaming. Add the leek and ham and fry gently, stirring from time to time, until the mixture is just turning light golden. Mix in the flour and cook through for a few minutes, stirring constantly to stop the mixture catching.
Warm the milk until it’s steaming but not boiling, then gradually add it to the ham mixture, stirring thoroughly between additions to avoid lumps. When all the milk is incorporated and the mixture is smooth, add a couple of gratings of nutmeg, to taste, and a grind of fresh black pepper.
Allow the mixture to simmer very gently for about 10 minutes (to ensure the flour is cooked), stirring occasionally until it’s very thick and coming away from the sides of the pan. Stir in the grated cheese until it’s melted.
Transfer the filling to a large bowl and cool briefly before covering with a layer of clingfilm pressed to the surface (this will prevent a skin forming). Once cool, put the bowl into the fridge for at least an hour until very firmly set.
To roll and coat the croquetas, put the beaten eggs into one bowl, the flour into a second, and the breadcrumbs into a third. Oil or flour your hands and roll spoonfuls of the mixture into cylinders or balls. Dip these first into the flour, then into the egg, then roll in the breadcrumbs until well coated. You may find it less messy to use one hand for the flour and breadcrumbs and the other hand for the egg.
Heat the oil in a large pan to 180°C, or until a cube of bread dropped into the oil browns within a minute. Line a plate with kitchen paper, then fry the croquetas in batches for a couple of minutes until light golden and crispy, turning them once if necessary. Lift out with a slotted spoon, drain on the kitchen paper and serve immediately.
Makes 15-20 croquetas