Servings: 2 quarts

4 (28-ounce) cans whole peeled tomatoes, preferably imported D.O.P. San Marzano tomatoes (see note) 4 (28-ounce) cans whole peeled tomatoes, preferably imported D.O.P. San Marzano tomatoes (see note)
1/4 cup extra-virgin olive oil, plus more for finishing ¼ cup extra-virgin olive oil, plus more for finishing
4 tablespoons butter (I use slightly less) 4 tablespoons butter (I use slightly less)
8 cloves garlic, minced (about 3 tablespoons) 8 cloves garlic, minced (about 3 tablespoons)
1 teaspoon red pepper flakes 1 teaspoon red pepper flakes
1 tablespoon dried oregano 1 tablespoon dried oregano
1 medium carrot, finely minced/food processed 1 medium carrot, finely minced/food processed
1 medium onion, finely minced/food processed 1 medium onion, finely minced/food processed
1 large stem fresh basil 1 large stem fresh basil
Kosher salt and freshly ground black pepper Kosher salt and freshly ground black pepper
1/2 cup minced fresh parsley or basil leaves (or a mix of the two) ½ cup minced fresh parsley or basil leaves (or a mix of the two)

Adjust oven rack to lower position and preheat oven to 300°F (165°C). Place tomatoes in a large bowl. Using your hands, crush the tomatoes by squeezing them in your fingers until pieces no larger than ½-inch remain. Transfer 3 cups of crushed tomatoes to a sealed container and reserve in the refrigerator until step 4.
Heat olive oil over medium heat in a large Dutch oven. Sweat onions and carrots, about 4 minutes. Add butter and garlic and cook, stirring, until softened and fragrant but not browned, about 2 minutes. Add pepper flakes and oregano and cook, stirring, until fragrant, about 1 minute. Add tomatoes and basil, and stir to combine. Season lightly with salt and pepper. Bring to a simmer over high heat.
Cover Dutch oven with lid slightly ajar and transfer to oven. You might need to adjust the oven temp up to get the level of simmering you need. The goal should be gentle continuous bubbling (I ended up at 325°F or even 345). Cook, stirring once every 1 to 2 hours, until reduced by about half and darkened to a deep red, 5 to 6 hours (reduce oven temperature if the sauce is bubbling too rapidly or the browned bits begin to turn too dark).
Remove from oven. Using tongs discard basil stems. Add reserved tomatoes to sauce and stir to combine. Season generously with salt and pepper and stir in minced herbs along with additional olive oil as desired. Serve immediately, or allow to cool at room temperature, transfer to airtight containers, and refrigerate for up to 1 week. Sauce can also be frozen in sealed containers for up to 6 months. To reheat, warm very gently in a saucepan with ½ cup water, stirring until it all melts and heats through.

This tomato sauce is only as good as the tomatoes you start out with. Look for whole peeled plum tomatoes packed in juice or puree. you'll never go wrong with D.O.P. San Marzano tomatoes imported from Italy, or go with a trusted brand of tomatoes if you have a favorite.  This tomato sauce is only as good as the tomatoes you start out with. Look for whole peeled plum tomatoes packed in juice or puree. you'll never go wrong with D.O.P. San Marzano tomatoes imported from Italy, or go with a trusted brand of tomatoes if you have a favorite.