Subtly sweet white balsamic and sharp black pepper make wonderful foils for ripe summer berries and stone fruit in this jewel-like salad.
Arrange plums on a platter. Scatter raspberries, strawberries, cherries, and grapes around them.
In a small pot, boil vinegar until reduced by half, about 5 minutes. Stir in 1 teaspoon water. Drizzle over fruit; sprinkle with pepper. Serve immediately, or wrap in plastic and refrigerate up to 4 hours.
