Peel and dice the onion. In this recipe you see them as more cubed but that is because I like my sauce chunky. It helps if you say it “chunk-ay.” Fun, huh? Want to know why onions make you cry? When you cut an onion, breaking the cells, the amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears.
Finely mince the 2 celery ribs. Once again, I went the chunky route. Some people use carrots in place of celery for a basic tomato sauce. You could do that but you would be wrong. Here is why, IMHO. The celery naturally adds salt to the sauce, as do carrots. Which I love. But carrots come with about 3x the sugar. And while I do add some sugar to this sauce, I want to control the salt and sugar separately, just highlighting the tomato’s natural umami.
Heat the olive oil. Add the onion, 2 celery ribs and a pinch of salt, and sweat them over a low heat for about 15 minutes.
While this is happening, open up those 2 cans of tomatoes and pour them into a large bowl. Now, you need to crush the tomatoes. You could puree them using some kitchen gadget, but the best tool for the job is your hands.
Mince the 4 cloves garlic, add them to the pot and cook them for about 1 minute.
Add in the teaspoon salt, sugar, and white balsamic vinegar, bring the heat up to medium and cook for a few minutes. Do not allow the ingredients to brown, you just want to evaporate the liquids.
Add in a tablespoon of tomato paste and cook that for a minute.
Add in the San Marzano tomatoes, bring it to a simmer and then turn it down to low. It is important to use San Marzano tomatoes for this, it’s the only acceptable choice. San Marzanos have a much thicker flesh, fewer seeds and the taste is stronger, sweeter and less acidic than say the Roma. The Roma is actually a cross between the San Marzano and two other varieties. So let’s use the original, baby!
Let the sauce cook for two hours, until it is thick, kinda like hot cereal. Adding in the fresh thyme when you have about 30 minutes left of cooking.
How gorgeous is this sauce? Now let’s get it on top of some pasta!