Pesto

Start with about 1 tablespoon (15 g) per person, then loosen it with a splash of the pasta cooking water. That portion is 87 kcal.

No: take the pan off the heat first, then stir pesto through the drained pasta with a little starchy cooking water. Prolonged frying or boiling can dull the basil flavour and make the cheese and oil separate.

Keep the jar covered in the fridge and use a clean spoon each time. For homemade pesto, transfer it to an airtight container, smooth the surface and cover it with a thin layer of olive oil; use within about 3–4 days.

Yes. Freeze it in small portions in an ice-cube tray, then transfer the frozen cubes to a sealed container; they are handy for adding straight to hot pasta or soup.

Spread it in a toasted cheese sandwich, stir a spoonful into soup, or brush it over vegetables before roasting. It is also a familiar topping for pizza and a filling for pesto chicken.

Walnuts, almonds or sunflower seeds work well in place of pine nuts; toast them lightly first for a deeper flavour. For a nut-free version, use sunflower or pumpkin seeds.

Traditional basil pesto usually contains pine nuts and hard cheese such as Parmesan, so it is not suitable for people avoiding either ingredient. Recipes vary, and some use cashews or other nuts instead.

The name comes from the Italian word pestare, meaning to crush or pound. Traditional pesto alla Genovese is made by crushing basil, garlic, pine nuts and cheese with olive oil, rather than cooking the ingredients.