In a large bowl, combine all ingredients and mix well. Cover and refrigerate until ready to serve!
16 oz Rotini pasta, 8 oz tomatoes, 8 oz mozzarella pearls, 1/2 cup fresh basil, 1/4 cup pesto, 3 tbsp olive oil, 2 tbsp balsamic vinegar, 1/2 tsp salt, 1/2 tsp pepper