Preheat the oven to 375°F. Lightly grease a 9x13-inch baking dish with cooking spray or olive oil.
In a blender or using an immersion blender, blend the cottage cheese and pesto until completely smooth and creamy.
Add the orzo, chicken, broccoli, cherry tomatoes, garlic, Italian seasoning, salt, pepper, bone broth, and blended pesto mixture to the prepared baking dish.
Stir well to evenly combine all ingredients.
Cover tightly with aluminum foil and bake for 15 minutes.
Remove the foil, stir gently, and continue baking uncovered for 15–25 minutes, or until the chicken is cooked through and the orzo is tender. Avoid overbaking, as the orzo can become mushy. If there is a small amount of liquid remaining, that's perfectly normal—the orzo will continue absorbing it as it rests.
Stir in the Parmesan cheese until melted and creamy. Taste and adjust the seasoning with additional salt and pepper and broth if needed.
Let the casserole rest for 5–10 minutes before serving.
Garnish with fresh basil and extra Parmesan cheese, if desired, and enjoy!