Heat closed contact grill 5 minutes.
Cut each roll in half horizontally; brush outside of each half with oil. Spread pesto on inside of both halves. Layer each sandwich with cheese and tomato. Sprinkle with salt and pepper.
When grill is heated, place sandwiches on grill. Close grill; grill 4 minutes or until bread is toasty and cheese is melted. Slice sandwiches on diagonal and serve warm.