The Test Kitchen

For vegetarians, when buying cheese, check the label to ensure the brands you buy are suitable – look for the use of non-animal rennet. The lemon juice in the pesto will discolour the mixture quickly, so it’s best to use the pesto as soon as possible.

If you need to make the pesto ahead of time, simply omit the lemon juice when preparing it in step 3, then store, covered tightly, in the fridge. When ready, stir the lemon juice into the pesto and continue with the recipe from step 4.