• 500 g (1 lb 2 oz) purple congo potato
• 3 garlic cloves, finely grated
• finely grated zest of 1 orange
• 80 ml (2½ fl oz/⅓ cup) extra virgin olive oil
• 40 ml (1¼ fl oz) Forum chardonnay vinegar

Peel, then chop the potato into equal pieces, place in a saucepan of cold water and bring to the boil. Reduce the heat to low and simmer until cooked through. Drain and transfer to a food processor with the remaining ingredients and process until smooth. Pass through a fine sieve. Set aside and keep warm.