How to make
First, fry the chopped onion in the heated oil and butter.
When it softens, pour the flour and sprinkle with salt, then mix briefly and pour the milk. Beat with a wire whisk, until all lumps are gone.
Finely chop the spinach with the garlic clove and add them into the pan. Season with salt and black pepper and stew, until the mixture thickens, by stirring constantly.
You should end up with a thick mixture that forms a path when you run a spoon through it that doesn't come together easily. Add the grated cheese and stir, until it has completely melted.
Remove it from the heat and transfer the mixture into a bowl. Cover it well with foil and when it has completely cooled, refrigerate it - leave it for 8 hours.
Remove the mixture and start shaping the croquettes. Scoop with a spoon and knead by hand until the characteristic shape is obtained. In case the mixture is sticky, moisten your hands slightly.
Roll the finished croquettes in the following sequence - flour, beaten egg and breadcrumbs.
Heat the oil on a high heat and fry, until a golden color is obtained. Place them onto kitchen paper to absorb the excess fat.
Serve them with sauce and a salad of choice.
The croquettes with spinach and crispy crust are ready.