How to Make It
In a bowl, toss the red onion with the vinegar and season with Maldon salt and white pepper. Let stand at room temperature until softened, 15 minutes. Drain.
Meanwhile, using a sharp knife, peel the oranges, removing all of the bitter white pith. Thinly slice the oranges crosswise, removing any pits. Arrange the oranges on a platter and scatter the red onion on top. Drizzle with the olive oil and season with Maldon salt and white pepper. Garnish with the basil and serve.