Toast the walnuts briefly in a dry frying pan over a medium heat until fragrant. Then leave to cool a little.
Finely grate the parmesan. Wash the rocket and dry it really well, then peel and roughly chop the garlic.
Put the walnuts, rocket, parmesan, garlic and lemon juice into a blender or food processor. Pulse briefly to a coarse mixture.
Slowly pour in the olive oil and keep blending until you have a creamy pesto that's still slightly chunky. If needed, adjust the consistency with a little more olive oil.
Season to taste with salt and pepper. If you like, chill the pesto briefly so the flavours come together.
Serve with pasta, roasted veg or on toasted bread. A spoonful also goes well with potatoes or beans.
Good to know
This pesto is slightly bitter, creamy and pleasantly direct in flavour. I especially like it when it isn't blended too smooth and still has some bite.
Swaps
Walnuts → almonds (more vitamin E, a little milder in flavour); parmesan → pecorino or another aged hard cheese made from cow's or sheep's milk (similar protein and calcium content); rocket → basil or parsley (milder, with their own plant compounds); lemon juice → a little more fresh lemon zest or mild white wine vinegar (fresh acidity if you have no lemon).
Allergens
Contains milk and walnuts; for small children, only offer it in an age-appropriate form because of the nuts, and during pregnancy make it with pasteurised or suitably labelled hard cheese.
