Heat olive oil in a large high-rimmed pan over medium heat. Add the minced garlic and cook for 2 minutes, stirring often. Pour in the uncooked orzo, stir, and toast for another minute.
Pour in the broth, season with black pepper and any additional seasonings as desired. Bring to a boil then lower the heat to simmer. Stir occasionally and cook for about 10-15 minutes until the orzo is cooked. Add additional broth as needed if it absorbs before the orzo is finished cooking.
Once the orzo is cooked and most of the liquid is absorbed, add the sliced cherry tomatoes and chiffonade fresh basil. Stir to combine. Mix in the basil pesto until well combined. Add the sliced fresh mozzarella balls. Stir to combine.
Serve immediately with additional basil as desired.