Season the tuna lightly on both sides with salt and pepper.
In a large skillet, heat the oil over medium-high heat. Add the tuna and sear to desired doneness, 3 to 4 minutes per side, depending upon the thickness.
Remove from the pan and place one steak on each of 4 plates. Spoon the caponata over the fish. Garnish with the cheese, chives and basil leaves, and serve immediately.
Yield: 4 servings