Cook pasta according to package instructions. Set aside 1 cup pasta water. Drain the rest of the water and set aside pasta.
Heat olive oil in a skillet under low medium heat.
Add garlic. Cook and stir until aromatic.
Stir in onions. Cook until translucent and aromatic.
Add the tomato paste. Cook and stir, about 4 minutes.
Add the heavy cream. Mix well.
Season with the chilli flakes, Italian seasoning, salt and pepper.
Add in the cheese and mix well.
Add unsalted butter for more flavor.
Put in pasta water and mix well.
Stir in the cooked pasta and fold to the mixture.
Transfer to a serving plate. Share and enjoy.