Asparagus Stalk Pesto

1. Set a large pan of salted water on to boil. Bend the asparagus spears till they snap. Set the tender tips to one side. Weigh the woody stalks – you should have around 100g stalks. Chop them into chunks around 2cm long. When the water is boiling, add the stalks and simmer for 4-5 mins till they're tender. Use a slotted spoon to scoop the stalks out of the water and leave to drain in a colander.

2. While the asparagus stalks cook, finely grate the Parmesan. Pick the mint leaves off their sprigs. Peel and crush the garlic clove.

3. Scoop the asparagus into a blender or food processor. Add the grated cheese, mint, garlic, walnut halves, lemon juice and 100ml olive oil. Add a pinch of salt and blend to make a smooth purée. If it's a little too dry, add a splash more olive oil. Taste the pesto and add a pinch more salt or a dash more lemon juice, if you think it needs it.

4. Scoop the pesto into a clean tub or sterlised jar and store in the fridge for up to 3 days. The pesto can also be frozen for up to 3 months – freeze it in ice cubes and you have small portions of pesto, ready for defrosting and tossing with pasta, adding to soups and stews, using to top baked potatoes and brushing over chicken or fish before grilling. 2 tbsp per person is a perfect serving size for pasta.