Chicken Marsala

4 chicken breasts
1 pound of mushrooms, sliced
1 cup marsala wine plus 2 tbsp. marsala wine
1 cup chicken broth
1 tbsp. virgin olive oil
1 onion, chopped
1 tbsp. Worcestershire sauce
4 tbsp. arrowroot or cornstarch
3 tbsp. fresh, chopped parsley
Salt and pepper to taste

Place the oil in a skillet and heat it. Add onion and sauté until the onion is translucent. Add mushrooms and 2 tbsp of the marsala wine. Continue to sauté. Add the mixture to the pressure cooker. Add the chicken breasts, wine, Worcestershire sauce, chicken broth, salt and pepper. Cover the pressure cooker and cook on high until the pot pressurizes. Lower flame and cook for 20 minutes, maintaining pressure. When finished cooking, take a cup of the liquid out and mix in the arrowroot (or cornstarch) until it is homogenous. Return the liquid to the pot and mix thoroughly while heating over a low flame. Remove chicken and sauce, sprinkle with parsley and serve.