Cook the tortellini: Bring a large pot of salted water to a boil. Cook tortellini according to package directions until al dente, about 7–8 minutes. Drain and rinse under cold water to stop cooking.
Prepare the veggies: While the tortellini cooks, chop tomatoes, cucumber, bell pepper, onion, and olives.
Combine ingredients: In a large mixing bowl, add cooled tortellini, veggies, mozzarella, and salami (if using).
Dress the salad: Pour Italian dressing over the top and toss until everything is evenly coated. Season with salt and black pepper to taste.
Chill & serve: Cover and refrigerate for at least 1 hour before serving to allow flavors to meld. Garnish with parsley before serving.