Peel and finely chop the garlic and the onion. Cut the Serrano ham into small pieces.
Melt the butter in a large frying pan and then add the onions. Saute for about 2 minutes or until translucent and soft. Season with salt and pepper and then stir in the flour. Cook for 1 minute and then remove from the heat.
Heat the milk in a saucepan. Once it comes to the boil, add it to the onions and flour and whisk to make a smooth sauce. Return to a medium heat and cook until you have a thick, creamy sauce. Season with salt, pepper and nutmeg. Add the chopped ham to the pan and cook for 4 to 5 minutes over a low heat.
Sit the mixture to the side and allow to cool slightly for 10-20 minutes.
Scoop the mix into a piping bag and pipe long sausages (approx 3cm diameter) over a lightly oiled tray or onto a silican mat and chill in the fridge for 20-30 minutes or until easy to handle.
In a small mixing bowl, beat the eggs until frothy. Season the flour in a second bowl with salt and pepper, and in a third place the breadcrumbs.
Cut the sausages of the ham mixture into croquettes 1 and a half inches long. Dip each one into the flour, dust off the excess, then dip into the egg wash, then roll through the seasoned breadcrumbs.
Place on a baking sheet and allow to set in the fridge until cold.
Heat your deep fat fryer to 180* or a large pan of sunflower oil. Test that the oil is hot by adding a little bit of bread or one of the croquettes to the oil and it should sizzle when added. Add the croquettes to the pan in small batches and cook for 3 to 4 minutes or until golden brown. Once cooked, place on kitchen paper to get rid of excess oil.
«Try adding 1cm diced manchego cheese for a different flavour and oozing texture. These can be precooked and reheated quickly in the oven.»