Cook bow tie pasta according to package directions.Chop the fresh basil and cut cherry tomatoes in halves.In a small bowl, add olive oil, pesto, balsamic vinegar, salt and pepper. Mix well with a whisk.In a large mixing bowl, add drained pasta, pesto mixture, drained mozzarella pearls, basil and tomatoes. Stir.Place in fridge for 2 hours and serve.