In a large skillet, heat 2 tablespoons oil on medium.
Add chicken to pan and cook 3 to 4 minutes or until chicken is no longer pink and reaches 165 degrees internal temperature.
Once cooked, take out chicken and set aside.
Add onions to pan and cook until translucent and fork tender.
Stir in mushrooms and pour in white wine.
Let cook for three to five minutes until white wine has reduced.
Pour in chicken broth, cornstarch, garlic powder, Italian seasoning, salt, and ground mustard, and cook, stirring occasionally, until sauce has thickened, about 7-10 minutes.
Stir in heavy cream.
Place chicken and juice back into the pan and stir until combined.
Serve over noodles. Garnish with chopped parsley, optional. Best when served warm.