Saute’ the pancetta or guanciale in olive oil on medium heat in a heavy skillet.
Add the onions, garlic, and hot red pepper flakes (or 1 dried peperoncino). Saute until browned, about 10 minutes.
Add freshly chopped tomatoes OR use imported Italian San Marzano tomato‘ passata' from the MUTTI brand.
It is entirely up to you to add wine at this point.
Gently stir the mixture until nicely blended together.
Bring to a simmer, reduce the heat to medium-low, and cook at a gentle simmer for about 20 minutes, until the sauce is thickened.
In boiling, salted water, cook your pasta (bucatini) for no more than 5 minutes until al dente and strain the water, leaving 1/2 cup of pasta water to add to the sauce.
Pour the strained pasta into a large, shallow, and wide pasta bowl. You can use any hefty shape of pasta that you prefer, but it is traditionally served with bucatini.
Add about a handful of freshly grated pecorino cheese to the simmering sauce on the stove and blend well. Then carefully pour the hot Amatriciana sauce onto the hot pasta.
Gently and thoroughly stir the sauce with the pasta.
Add the reserved pasta water a little at a time to loosen the sauce to your desired consistency. Taste. Add more cheese if you like. Make sure you have a lot of grated pecorino cheese to take to the table also.