Position racks in the lower third and middle of the oven and heat to 450 F. Lightly coat 2 baking sheets with olive oil cooking spray.
In a bowl, toss the eggplant with 1 teaspoon of the olive oil. Spread the eggplant in a single layer on one of the prepared baking sheets.
In the same bowl, toss the zucchini with 1 teaspoon of the olive oil. On the second baking sheet, spread the zucchini in a single layer and arrange the tomato halves cut-side up. Rub a bit of olive oil left in the bowl on the top of the tomato halves. Place the eggplant on the lower rack and the zucchini and tomatoes on the middle rack of the oven. Roast for 8 minutes. Turn the eggplant, zucchini and tomatoes and roast until softened, about 8 minutes longer. Set aside to cool.
Peel the roasted bell peppers and dice into 1/2-inch pieces. Set aside.
To make the vinaigrette, in a blender or food processor, combine the roasted tomatoes, shallot, balsamic vinegar, salt and pepper. Process until smooth. With the motor running, slowly add the remaining 5 teaspoons olive oil in a thin stream until emulsified.
In a large bowl, stir together the roasted eggplant, zucchini, bell peppers and the lemon zest. Add the vinaigrette and toss just to combine. Sprinkle with the basil and parsley. Cover and refrigerate or serve at room temperature.