Char bell peppers over gas flame or in broiler until blackened on all sides. Wrap in paper bag and let stand at least 10 minutes. Peel and seed. Rinse if necessary; pat dry. Cut into 3/4-inch-wide strips. Place in bowl. Mix in oil, vinegar and orange peel. Season with salt and pepper. Let stand 1 hour. (Can be prepared 1 day ahead. Cover and refrigerate. Bring to room temperature before serving) Chop basil; mix into peppers and serve.