Do not cut off the roots or peel the skin before cooking or the beetroot will 'bleed' and lose its distinctive colour. Simply twist off the roots about 3cm from the end and wash any soil or grit away. The skin should be peeled off before serving.
Boil for 1-2 hours in salted water, or bake in buttered paper at 160°C/ 325°F/ Gas mark 3 for 2-2˝ hours. The skin should slide off easily once cooked.
Alternatively, slice them and sauté them gently, moistening them with wine vinegar to set their colour and give them a perfect flavour.