Set the diced eggplant in a steamer basket. Set the basket over 1 inch of water and bring to a simmer. Cover and steam the eggplant until tender, 12 minutes; drain well.
In a large skillet, combine the tomatoes with the garlic, cumin and paprika and simmer over moderate heat until thickened, 5 minutes. Add the tomato sauce and the eggplant and simmer, gently stirring a few times, until the eggplant is flavored with the sauce, 3 minutes. Remove from the heat and stir in the vinegar. Season with salt and pepper; add the lemon zest, cilantro and parsley. Serve warm or at room temperature.