There are many variations of this recipe as it's one of the staple pasta recipes. In my version I'm also adding one small anchovy to create more complex taste. Originally this dish was known as pasta alla gricia, or griscia, as it came from the village of Grisciano where shepherds made their meal using pasta, guanciale, and pecorino. It was in the nearby town of Amatrice that tomato sauce was added in the late 1600s and the dish was officially named amatriciana.
This long cooking process will bring natural sweetness from tomatoes.