Cook the cheese tortellini according to package instructions. Drain and rinse under cold water to cool. Set aside.
In a large mixing bowl, combine the cooled tortellini, cherry tomatoes, cucumber, bell pepper, red onion, and black olives.
Add the pesto sauce and olive oil to the bowl. Toss gently to coat all the ingredients evenly.
Season with salt and pepper to taste. Mix well.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld.
Before serving, give the salad a gentle toss and garnish with fresh basil leaves if desired.