Heat oil.
Caramelize onions.
Saute mushrooms with balsamic vinegar.
Add onions to the mushrooms.
Season with salt and pepper.
Add garlic .
Add chicken.
Add chicken stock, Marsala, and white wine. Cook until reduced by half.
Add cream and bring to a boil.
Turn down heat and simmer to skim away any impurities.
Cook rigatoni al dente.
Add drained rigatoni to chicken mixture in pan and finish with basil-parsley mix, parmesan cheese, garlic butter, and salt and pepper.
Add more Marsala for flavor as needed.
Place in pasta bowl and garnish with parmesan shavings and chopped parsley.
