Prepare the pasta according to the package directions. In the final 3 minutes of cooking, add broccoli to the pasta and cook the remaining time. Drain pasta.
In a 12-inch skillet, heat the oil over medium-high heat. Add the chicken to the skillet and cook for 2 minutes before flipping and cooking an additional 2 minutes. Remove the chicken pieces from the pan and set aside.
Melt butter in the skillet over medium heat. Whisk in flour until lightly browned, about 1 minute.
Gradually whisk in chicken broth and milk, and cook, whisking constantly until incorporated, about 1-2 minutes. Stir in heavy cream, garlic powder, and Italian seasoning until slightly thickened, about 1-2 minutes.
Add in ½ cup Parmesan until well combined, about 1 minute. If the mixture is too thick, add more milk as needed.
Stir in the pasta, broccoli, and chicken. Serve and sprinkle with additional Parmesan cheese.
Preheat the thermos container with boiling water. This step is optional, but it helps.
Heat the chicken Alfredo in the microwave or stovetop to a piping-hot temperature.
Drain the water from the thermos.
Fill the thermos with the very hot chicken and broccoli Alfredo.
Close the thermos container and pack it inside a lunch bag with your choice of snacks.
