How to Make It
In a large, deep skillet, heat the 1/4 cup of olive oil until shimmering. Add the celery, onion and garlic and cook over moderate heat until just softened, 4 minutes. Add the tomato sauce, wine, vinegar, artichokes, olives, pine nuts, sugar and capers and season with salt and pepper. Simmer until the vegetables are tender and the liquid is reduced, 8 minutes. Stir in the basil and let cool.
Light a grill or preheat a grill pan. Rub the fish with olive oil and season with salt and pepper. Grill over moderately high heat, turning once, until cooked through, about 9 minutes. Transfer the fish to plates, top with the caponata and serve.