Sauce
Into a saucepan, pour the hot water, add the pasta, the salt, the olive oil, give it a mix and let it all cook for 8 minutes.
After this indicated time, drain all the water and set the pasta aside.
In a skillet, add one drizzle of olive oil, the onion chopped into small cubes and the tomato paste, stir for 3 minutes. Add the water and stir until it starts to boil.
Once you’ve done that, add the milk, the heavy cream, the grated cheese and the unsalted butter, stir very well until combined.
Now, add all the pasta and stir until incorporated.
Finish with parsley to taste.
Serve.