Heat olive oil in a large skillet over medium heat. Add the chopped onion and garlic, sautéing until fragrant. Stir in the cherry tomatoes and cook for 2–3 minutes until softened.
Add the orzo to the pan and toast for about 1 minute. Pour in the chicken broth and stir well. Cover and let it simmer, stirring occasionally, until the orzo is tender and most of the liquid is absorbed.
Stir in the shredded chicken and Italian seasoning. Cook for another 3–4 minutes, allowing the flavors to meld together.
Turn off the heat and mix in the grated Parmesan cheese. Season with salt and black pepper to taste.