Bring a medium pot of salted water to a boil. Add 1 cup of orzo and cook according to package instructions, about 8-9 minutes, until al dente. Drain in a colander and rinse briefly under cold water to cool.
While the orzo cools, halve the cherry tomatoes and chop the fresh basil leaves. If using, slice grilled chicken or turkey into bite-sized pieces. Drain and pat dry the fresh mozzarella balls.
In a large mixing bowl, combine the cooked orzo, cherry tomatoes, mozzarella balls, and chopped basil. Add 1/2 cup pesto sauce and 2 tablespoons olive oil. Toss gently until evenly coated. Season with salt and pepper to taste.
Cover the bowl and refrigerate the salad for at least 30 minutes to meld flavors. Serve chilled or at room temperature. Top with grilled chicken or turkey slices if desired.
