Preheat broiler. Line broiling pan (without rack) with foil. Cut each pepper lengthwise in half; discard stems and seeds. With hand, flatten each pepper half. Place peppers (half the amount at a time, if pan is small), cut-side down, in broiling pan. Place pan in broiler 5 to 6 inches from source of heat, and broil peppers until charred and blistered, 10 to 15 minutes. Wrap foil around peppers and allow to steam at room temperature 15 minutes or until cool enough to handle. (Repeat with remaining peppers.)
Meanwhile, prepare pasta in boiling salted water as label directs. Drain pasta; rinse with cold water, and drain again. Set aside.
Remove peppers from foil. Peel off skin and discard. Cut peppers into 1/2-inch pieces.
In nonstick 12-inch skillet, heat 1 tablespoon oil over medium heat until hot. Add onion and cook 6 minutes or until tender, stirring occasionally. Add zucchini and 1 tablespoon oil, and cook 7 minutes or until zucchini are tender-crisp, stirring frequently. Add eggplant, 3/4 teaspoon salt and remaining 2 tablespoons oil, and cook 8 minutes or until eggplant is tender, stirring frequently.
Transfer vegetables to large bowl; stir in tomatoes, basil, capers and 1/2 teaspoon salt. Add pasta; toss well. Serve salad warm, or cover and refrigerate until ready to serve. Makes 12 servings.
* Each serving: About 225 calories, 6g total fat (1g saturated), 0mg cholesterol, 285mg sodium.