Raw Tuna with Citrus Dressing

• 2 oranges
• 1 Seville orange
• 1 lemon
• a

Cut across the tops and bases of the fruit, place them on a board and cut away the skin and pith as though removing the staves of a barrel. Remove the segments of the fruit from between the pithy walls and pick out any pips. Season with the chilli flakes, plenty of sea salt and freshly ground black pepper and whisk vigorously to break up the fruit before adding the balsamic vinegar and olive oi