Peel the oranges whole, making sure that the white skin is peeled off with the peel. Now cut the oranges into thin slices and arrange them decoratively on two large plates. Pour the onion rings over the orange slices.
Mix a dressing out of oil and vinegar and drizzle over the orange carpacchio. Sprinkle with the freshly ground black pepper and serve. A spicy and somewhat unusual starter variant that always provides my guests with a - pleasant - surprise.