Ingredients :

• Passata — Passata is just pureed and strained tomatoes—smoother than crushed, denser than industrial coulis. For arrabbiata, it’s the right choice: it reduces well and clings to the pasta without being grainy. Cirio is solid, but any Italian passata with a short ingredient list will do.
• Chili flakes — Flakes, not powder. Powder gives a diffuse and uniform heat; flakes provide small peaks of heat depending on where they land. It changes how you experience the spiciness. One teaspoon to stay reasonable.
• Pecorino Romano — You could use parmesan. Some do. But Pecorino Romano is saltier, more robust, with a slightly sharp edge that pairs well with the acidity of the tomato. If you can’t find it, ordinary Pecorino can work; parmesan also works but the profile is milder, less sharp.
• Garlic — Two cloves, smashed flat with the side of a knife—not minced. Smashed, the garlic gently infuses the oil and can be easily removed before serving if needed. Minced, it would melt into the sauce and become more aggressive. Here we want the aroma, not the pieces.