You'll have to move quickly on this recipe once it gets going so make sure you have everything ready to go when you start. Grate your pecorino and have everything else to hand.
Start by bringing a wide and shallow pot of water with a good pinch of sea salt to the boil. You want just enough water in the pan to cover the pasta at a nice rolling boil.
Add your pasta to the pan and cook for the time specified on the pack (it won't be long). Once this is done, reserve a cup of the pasta water and drain.
Melt a knob of butter in another wide-rimmed pan and twist some good grinds of black pepper in. Cook on a medium heat for a couple of minutes.
Add the pasta water to the pan along with the pecorino and whisk well until all dissolved, about 4 minutes. Add the pasta and stir well til all incorporated.
If using, spoon the double cream in and again stir well. Serve immediately with some extra parmesan on top, if you fancy. YUM!