Cook the macaroni in salted water according to the package instructions (mine took 12 minutes).
Drain, toss the pasta in the oil to stop it sticking and tip onto a plate whilst you make the sauce.
Melt the butter in the same pan.
Add in the flour and stir/whisk constantly for 1-2 minutes
Add in the milk, a little at a time and always stirring, until all the milk is used up.
Keep stirring on the heat until your sauce is nice and thick.
Add in the cheese and keep stirring until it has all melted and the sauce is smooth.
Take off the heat and season with pepper, smoked paprika, and salt if you like.
Turn the heat down to low, tip the cooked pasta back into the sauce and stir to coat it evenly.
Let the pasta warm through then devour with gusto :D