Melt the butter in a saucepan over medium heat. Add the flour and stir for 2 minutes to make a roux.

Gradually add the warm milk, whisking constantly to avoid lumps. Cook, stirring continuously, for 8–10 minutes until the béchamel is very thick.

Stir in the diced ham. Season with nutmeg, salt and white pepper.

Pour into a flat dish, press plastic wrap directly onto the surface and refrigerate for at least 2 hours until firm.

Shape the chilled mixture into cylinders or oval shapes (about the size of a finger).

Dip each croqueta in beaten egg, then breadcrumbs. Repeat for a double coating.

Deep-fry at 180°C for 2–3 minutes until deeply golden. Drain on paper towels. Serve immediately.