For marinade, in a screw-top jar, combine oil, vinegar, chopped basil, thyme and marjoram.Add sugar, if desired.Cover and shake well.Set aside ¼ cup in refrigerator for dressing.
Place meat in a resealable plastic bag and set in a shallow dish.Pour marinade over meat and seal bag.Marinate in the refrigerator 4-6 hours, turning bag occasionally.
Meanwhile, remove stems from the red peppers.Halve lengthwise, remove seeds and membranes.Cut peppers into 1-inch wide strips.
Preheat grill to medium.Drain meat and reserve marinade.Grill meat uncovered to desired doneness, turning once.Allow 14-18 minutes for medium rare (145 degrees F) and 18-22 minutes for medium (160 degrees F).Add pepper strips the last 8-10 minutes of grilling, turning and brushing with marinade occassionally during the first 5 minutes of cooking.Discard any remaining marinade.
Let steak rest for 5 minutes and then thinly slice.To serve, arrange basil leaves and pepper strips on rolls and then top with steak slices.Drizzle sandwiches with vinaigrette dressing.