In a large mug or a bowl (you need a larger bowl because the water bubbles up while the pasta is cooking), add pasta, salt, pepper and water and microwave for 4-5 minutes till the pasta is fully cooked. Check at 4 minutes and then cook in 30 second intervals till the pasta is done.
Add cornflour and milk and mix well. Add cheese, give it a quick mix and microwave for another minute. Mix well and serve immediately.
The cornflour can be skipped, but it helps make a thick sauce that coats the pasta
If you don't finish this in one go, you can save it for later. To reheat, add a splash of milk, microwave for a minute, mix and eat.