Cook the pasta as per instructions of the package. Finish 2 minutes before the indicated time (Al dente). We'll finish the cooking in the oven.

While the pasta is cooking, dice the chorizo/sausage, tomatoes and onion.

in a medium pan, heat the oil, add the butter and fry the chorizo/sausage.

When the chorizo is fried, remove it from the pan and set it aside. In the same pan, add the diced onion and fry until brown.

Once the onion is browned, add the all-purpose flour, stir well to combine the flour with the butter and then add the milk. Mix for a while and season with salt and black pepper. Let it cook for about 5 minutes until thick.

5 minutes later, add the grated cheese and cook for more 2 minutes. After that, set the sauce aside.

Let's assemble the pasta. In a large bowl, mix the pasta with part of the fried chorizo and tomatoes.

Add half of the sauce and mix well.

Add this to a large baking pan, add the remaining sauce on top of it. Add the fried chorizo and tomatoes. Sprinkle orégano and grated cheese on top of it.

Bake it in a pre-heated oven at 428ºF (220º C) for about 20 minutes.

Serve while hot.