Make the caponata up to 5 days ahead and keep it covered in the refrigerator. Before serving, bring back to room temperature for the best flavor. To toast the pine nuts, heat them in a dry skillet over medium heat until fragrant, 3 to 5 minutes, shaking the pan now and then.
•Heat 4 tablespoons of the grapeseed oil in a large, heavy skillet over medium-high heat. Add the eggplant cubes and sauté until nicely browned, about 10 minutes. Remove with a slotted spoon and drain on a wire rack set over a drip pan or paper towels. •Add the remaining 1 tablespoon oil to the pan and sauté the fennel and onion until lightly browned, about 5 minutes. Add the garlic and cook for 1 minute. Stir in the tomatoes, scraping up any brown bits from the bottom of the pan. •Add the sautéed eggplant, pine nuts, and raisins and mix gently so that you don’t break up the eggplant. Add 2 teaspoons of vinegar, then taste and season with salt, pepper, and vinegar as needed. •Let cool to room temperature before serving.