2 (24-ounce) cans
whole, peeled San Marzano tomatoes
2 teaspoons
kosher salt
10 to 12
basil leaves, plus more for serving
1
medium yellow onion, quartered
1 teaspoon
Italian seasoning
6 tablespoons
salted butter
1 teaspoon
red pepper flakes, plus more for serving
16 ounces
uncooked fusilli pasta
Freshly grated Parmesan, for serving (optional)
Method
In a large pot set over medium heat, combine the whole tomatoes and their juices, salt, basil, onion, Italian seasoning, butter, and red pepper flakes. Bring to a simmer, then reduce the heat to medium low. Cook, stirring occasionally until the sauce has thickened and the onion is softened, about 1 hour.
Once the sauce has cooked for about 45 minutes, bring a large pot of water to a boil over high heat and salt it. Add the pasta and cook until al dente according to package instructions. Reserve ΒΌ cup pasta water, then drain.
Using a slotted spoon, remove the onion from the sauce and discard. Using an immersion blender, blend the sauce in the saucepan until mostly smooth. (Alternatively, transfer the sauce to a blender, let cool briefly, and blend until smooth.)
Add the pasta and reserved pasta water to the sauce and toss to coat.
Divide the pasta among six bowls. Garnish with basil, red pepper flakes, and Parmesan, if using.