1 tablespoon (15ml) extra-virgin olive oil
2 large shallots (about 3 ounces; 90g), thinly sliced
One (24.5-ounce; 700g) bottle tomato passata (see note)
4 ounces (1/2 cup; 115g) ‘nduja (see note)
1 pound (450g) dried ziti, candele (broken into 3-inch pieces) or other short tubular pasta
2 ounces (60g) finely grated Pecorino Romano cheese
In a large skillet, heat olive oil over medium heat until shimmering. Add shallots, season lightly with salt, and cook, stirring frequently with a wooden spoon, until shallots are softened but not browned, 5 to 7 minutes.
Add passata, and make sure to use up all of the tomato in the bottle by adding 1/4 cup (60ml) water to the empty bottle, screwing on the lid, shaking the contents, and then adding tomato-water mixture to the skillet. Bring to simmer, season lightly with salt, and cook, stirring occasionally until sauce is slightly thickened, 12 to 15 minutes.
Add ‘nduja, and use wooden spoon to break up and stir into sauce. Cook, stirring constantly, until ‘nduja is fully emulsified and incorporated in sauce, about 1 minute.
Meanwhile, in a pot of salted boiling water, cook pasta until just softened on the exterior, but well shy of al dente, and still uncooked in the center (about 3 minutes less than the package directs). Using a spider skimmer, transfer pasta to sauce, along with 1/2 cup (120ml) pasta cooking water. Alternatively, drain pasta using a colander or fine-mesh strainer, making sure to reserve at least 1 cup (240ml) pasta cooking water.
Increase heat to high and cook, stirring and tossing rapidly, until pasta is al dente and sauce is thickened and coats noodles, about 2 minutes, adding more pasta cooking water in 1/4 cup (60ml) increments as needed. Remove from heat, add half of grated cheese, and stir rapidly to incorporate. Season with salt to taste. Serve immediately, passing remaining grated cheese at the table.