1. In a saucepan heat the milk with the heavy cream and in another saucepan add the butter and flour to make a blond rue. (the roux are the basis for tying various sauces in order to prepare a roux we need fatty material and flour)
2. Once the milk comes to a boil, pour half of it into the saucepan with the roux and then transfer the mixture to the pot with the milk and continue to stir until béchamel thickens.
3. Then gradually pour in the grated cheddar cheese.
4. Season with salt and pepper.
5. In a saucepan with a lot of boiling water boil the spaghetti about 5 minutes.
6. Strain the spaghetti and put in a bowl.
7. Add 2-3 tablespoons of olive oil and stir so that they do not stick.
8. Add half of the amount of the béchamel into the spaghetti, stir well and pour the mixture into a pyrex.
9. In a bowl add the panko breadcrumbs, the grated gruyere, the grated parmesan and the paprika.
10. Mix all the ingredients.
11. Add a little more béchamel to the mixture and place on top to cover the entire surface of the crust with the cheeses.
12. Bake in a preheated oven in the grill at 220 C degrees for 10 minutes.