Preheat oven to 350°F.

Pierce the skin of the eggplant with a large kitchen fork. Place in an ovenproof dish and bake for 1 hour until the eggplant is tender and about to collapse. Slice the eggplant in half lengthwise and allow to cool. Using a large spoon, scoop out the pulp, then chop it. (If excessively seedy, remove some of the seeds.) Set aside.

Heat the oil in a large nonreactive skillet over medium heat. Add the garlic and sauté until golden, about 1 minute. Add the tomatoes and roasted pepper. Season with salt and pepper. Bring to a simmer and cook for 10 minutes. Add the eggplant pulp and cumin. Cook an additional 20 minutes, stirring occasionally until most of the juice has evaporated but the mixture is still moist. Add the lemon juice and set aside.

Prepare the yogurt sauce: Pulse the tahini and garlic in a food processor until smooth. Add the remaining ingredients and pulse until blended.

To prepare the pitas, use scissors to carefully trim away the edges of each pita. Pull the two layers apart and cut each layer into 8 wedges. Toast wedges in a broiler or toaster oven. Serve the eggplant and sauce with the warm pita wedges and a variety of oil-cured olives. This dish can be served as a snack with drinks or as a first course.