Using the same skillet, reduce the heat to medium and add the remaining tablespoon of avocado oil. Add the onions and sauté for 5 minutes, until soft. Then add your garlic and cook for about 1 minute more. Last, add your mushrooms and cook until tender, about 8 minutes. Stir in the wine and bring to a simmer for 5 minutes.
Stir in the chicken broth and heavy cream. Add the chicken back to the skillet and spoon some of the sauce over the chicken. Season with salt and pepper to taste. Simmer for about 10 minutes or until thickened.