Baked Beetroot with Tarragon

Cut leaves from beetroot. If the leaves look fresh, cook them separately by rinsing and cooking gently in a heavy closed pan until soft. Eat them with salt, lemon juice and a dribble of olive oil. Anyway, back to the roots. Wash the beetroot in plenty of cold water, taking care not the break the skin, then drain well. Brush peanut or grapeseed oil over the inside of a lidded cast-iron casserole and add the beetroot in a single layer. Cover and cook in the oven (Gas4/180C) or 1-2 hours depending on size, then remove from oven. Leave uncovered until cool enough to handle. Peel the beetroot and arrange, whole or cut into quarters in a hot serving dish. Melt butter in a small pan, add chopped fresh tarragon and snipped chives and stir round. Pour over beetroot and sprinkle with sea salt crystals before serving.