Spinach walnut pesto

Step 1: Roast 1 ¾ oz walnut pieces in a dry frying pan over a medium-low heat, shaking the pan often, for 3–4 minutes until they smell toasty. Let them cool.

Step 2: Put 9 oz baby spinach, 1 clove garlic, 2 tbsp lemon juice, the walnuts, ⅔ oz parmesan cheese and ½ tsp salt in a blender or food processor and blend until smooth, scraping down the sides once or twice.

Step 3: With the motor running, pour in ½ cup extra virgin olive oil in a thin stream until the pesto is as thick or loose as you like it. Taste and add more salt if needed.

Step 4: Toss through freshly cooked, drained pasta with a splash of the cooking water, or stir a spoonful into a bowl of vegetable soup or an omelette.

Step 5: Store it in a clean jar, covered with a thin film of olive oil, in the fridge for up to a week. For longer, spoon it into a sealable container and freeze; you can scrape out a single spoonful without thawing the lot.