- Pour olive oil into a large pot and heat over medium heat.
- Add pureed onion, garlic and crushed red pepper flakes to onion mixture. Cover with lid and allow to swear for 5-10 minutes. You do NOT want any color on the mix. You just want them to get fragrant and translucent.
- Add the pureed tomatoes to the onion and garlic mixture.
- Cook for 20-25 minutes, cook covered over low medium heat. You want the tomato sauce to very slowly simmer.
- Tear basil leaves with your hands into the sauce and taste for seasoning. If the sauce seems to thick, you can thin out with water or chicken stock.