Season the chicken thighs with ¼ teaspoon of salt, ¼ teaspoon of pepper, onion powder, garlic powder, and ¼ teaspoon of thyme. Let them sit for 15 minutes.
Bring 4 quarts of water to a rolling boil. Add pasta and stir occasionally. Boil until al dente (8-10 minutes) and drain immediately.
Sear the chicken thighs in 1 tablespoon of olive oil in a large pot over low heat for about 12 – 15 minutes until they’re golden brown. Remove the chicken from the pot and slice it into strips.
Stir-fry the mushrooms with ½ tablespoon of olive oil. Once the mushrooms are cooked, transfer them into a small bowl.
Add butter to the same pot, then saute onion and garlic for 3 minutes. Add in flour, chicken broth, milk, and heavy cream. Season the mixture with the remaining salt, pepper, nutmeg, thyme, and Italian seasoning. Then bring to a boil.
Add the pasta and mushrooms and reduce to a simmer for an extra 2-3 minutes.
Stir in the parmesan cheese and parsley to the pot. Stir so it combines into the mixture. Add chicken to the pot.
Serve. Garnish with fresh parsley and pepper if desired.