1. Wrap each beetroot in foil and add a little balsamic vinegar and pepper to each one before sealing tightly. Place on a baking tray and roast for 1 hour or until tender.

Meanwhile, make the pesto.

2. Add the coriander and cashews to a food processor and blitz until finely chopped. Then with the motor running add the olive oil in a steady stream through the open feeder shoot and process until it's the consistency of pesto. Be careful not to leave it too long or it will liquidise - we're not trying to make a coriander milkshake! Stir through the lemon juice and set pesto aside while you prepare the beetroot.