Bake whole peppers on an aluminum-foil-lined baking sheet 20 to 25 minutes at 450°, or until peppers appear blistered and are slightly blackened. Place peppers in a heavy-duty zip-top bag and seal. Let stand 10 minutes or until cool. Peel peppers, then remove and discard seeds. Cut into wedges. Drizzle with olive oil and balsamic vinegar, then sprinkle lightly with salt and pepper.