Step 1

Arrange 2 racks to divide the oven into thirds and heat the oven to 425°F. Meanwhile, dice 2 medium eggplant into roughly 3/4 to 1-inch pieces (about 9 cups). Transfer to 2 large rimmed baking sheets.

Step 2

Drizzle each baking sheet with 2 tablespoons olive oil, season with 1/2 teaspoon kosher salt, and toss to coat. Arrange into a single layer. Roast, tossing halfway through, until the eggplant is tender and golden-brown, about 25 minutes total. Meanwhile, peel and dice 1 medium yellow onion (about 2 cups). Thinly slice 1 medium celery stalk crosswise (about 1/2 cup).

Step 3

Heat the remaining 2 tablespoons olive oil in a large skillet over medium-high until shimmering. Add the onion and cook, stirring occasionally, until tender and light golden-brown, about 4 minutes.

Step 4

Add the celery, 1 (about 14-ounce) can whole peeled tomatoes and their juices, 1/4 cup red wine vinegar, and 1 tablespoon granulated sugar. Bring to a simmer, using a wooden spoon to break up the tomatoes into bite-sized pieces and stirring to dissolve the sugar. If the eggplant is finished roasting, proceed to the next step. Otherwise, remove the skillet from the heat until eggplant is ready, then bring the tomato mixture back to a simmer over medium-high before proceeding.

Step 5

Add the eggplant, 1/4 cup pine nuts, and 3 tablespoons drained capers to the tomato mixture and bring to a boil. Reduce the heat to medium-low. Cover and simmer, stirring occasionally and adding a tablespoon of water or two if the mixture is too thick or sticking to the bottom of the pan, until the flavors meld, the mixture is saucy, and the eggplant is super tender and creamy, about 30 minutes. Meanwhile, drain 1 (6-ounce) can pitted whole black olives and if desired, coarsely chop.

Step 6

Add the olives to the eggplant mixture and stir to combine. Serve warm or chilled. Pick and tear the leaves from 2 small fresh basil sprigs into bite-sized pieces and scatter over the caponata before serving.