1. Preheat the oven to 200°C/fan 180°C/gas 6. Butter a 2 litre ovenproof dish. Using a food processor, or a sharp knife, finely slice the beetroots and sweet potatoes into thin rounds. 2. Begin layering the root vegetables alternately in the dish. Start with a layer of beetroot, then sweet potato, and continue until you have used them all up. 3. Mix the garlic with the cream. Add the thyme and nutmeg and season generously. 4. Slide the dish into the oven and bake for 1 hour 15 minutes, until the top is golden, the cream has thickened and the vegetables are tender – check this by piercing them with a knife. If the knife goes through easily and the beetroot and sweet potato start to mash, it’s ready. Remove and leave to cool slightly before serving. An amazing combination.