How to Make It
In a jar, combine the pistachios with the shallots, capers, vinegar, sugar, pink peppercorns and the 2 tablespoons of olive oil; season with sea salt. Refrigerate the relish overnight.
Arrange the tomato slices on plates. Drizzle lightly with olive oil and sprinkle with sea salt. Stir the relish and spoon it over the tomatoes. Garnish with basil leaves and serve.