Heat the olive oil in a large skillet or pan with a lid over medium heat.
Add the mushrooms and onion. Cook for 5–7 minutes until they are soft and lightly browned.
Stir in the garlic and Italian seasoning. Cook for 30 seconds until it smells good.
Add the dry pasta, chicken broth, and milk.
Bring to a boil, then lower the heat to a simmer. Cover the pan.
Cook for 10–12 minutes. Stir a few times until the pasta is tender and the liquid is mostly gone.
Stir in the shredded chicken and Parmesan cheese.
Cook for 2–3 more minutes until the chicken is hot and the sauce is creamy.
Season with salt and pepper to taste and serve with parsley if you like.