Storage: Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. Reheat gently with a splash of water or olive oil.
Substitutions: For a vegetarian version, omit the anchovies and add a pinch of smoked paprika or extra capers for depth. You can substitute dry spaghetti for fresh pasta; adjust cooking time accordingly.
Tips: Don't skip the step of cooking the whole garlic cloves; they add a sweet, mellow background flavor that balances the sharpness of the chopped garlic. If you prefer a spicier kick, increase the red pepper flakes.
Variations: Some cooks add a splash of white wine to deglaze the pan before adding the tomatoes for extra acidity.