Balsamic Chicken Breasts with Creamy Mushroom Sauce

INGREDIENTS

Medium-large Boneless skinless Chicken Breasts ((almost 2 pounds))

Kosher Salt and ground Black Pepper

4 tbsp

Unsalted Butter (divided)

1 1/2 cups

chopped Yellow Onion

8 oz

Cremini Mushrooms (cleaned* )

1 cup

Low Sodium Chicken Stock

1 tsp

fresh Thyme leaves

1/2 tsp

Crushed Red Pepper Flakes

2 tbsp

Balsamic Vinegar

1/2 cup

Heavy Cream