This has to be one of my favourite ways to make pesto – broccoli is the perfect base alongside chilli and walnuts. I’ve given quantities to serve four below, because even a small head of broccoli makes a lot of pesto, but if you’re cooking for one or two, I’d suggest just reducing the amount of pasta, and stashing the remaining pesto in the fridge for up to 2 days, or in the freezer in portions for future emergencies.