Heat the olive oil in a stock pot on medium heat. Add in the garlic and onion and saute until fragrant, just before browning, about 3 minutes.
Add in the tomato paste and stir into the onions. Let it cook for about a minute.
Add in both cans of sauce. If using two cans of San Marzano tomatoes, add ½ cup water.
Add in all of the dried herbs and spices. Combine all together.
Bring to a boil for about 5 minutes and then cover and reduce to a simmer.
If you used only crushed tomatoes, simmer for 30 minutes. If you used any San Marzano tomatoes, simmer for one hour.
While cooking, stir about every 15 minutes. Crush any large tomatoes with a wooden spoon. If the sauce starts to boil, even on a low simmer, turn the heat off for a bit and leave covered.
Add in fresh herbs or any meat 15 minutes before finishing.
See detailed instructions above for any troubleshooting.