Preheat indoor electric grill. On eight 6-inch skewers, alternately thread eggplant, zucchini, sweet pepper, and onion, leaving 1/4 inch between pieces. Brush with salad dressing. Combine the Parmesan cheese and bread crumbs; place on a piece of waxed paper. Roll the kabobs in the crumb mixture to coat evenly.
Place kabobs on the grill rack. If using a covered grill, close lid. Grill until zucchini is crisp-tender. (For a covered grill, allow 4 to 5 minutes, giving kabobs a quarter turn once halfway through and placing tomatoes on ends of skewers the last 1 minute of grilling. For an uncovered grill, allow 8 to 10 minutes, turning occasionally to cook evenly and placing tomatoes on ends of skewers the last 2 minutes of grilling.) Makes 4 servings.