Preheat the oven to 120° C. Finely slice the beetroot, parsnips, carrots and sweet potato with a potato peeler or mandolin. Toss with the olive oil. Spread over lined baking trays and sprinkle the salt, cumin and coriander over. Bake for about 40 minutes or until crispy.
Mix the mayonnaise, harissa and orange zest together and serve with the root chips and an icy cold Castle Light.