Place 2 tablespoons of butter in a large skillet over medium heat. Add onions and sauté until lightly brown, then remove onions from pan and set aside.
Pat chicken pieces dry, dredge in flour and shake to remove excess flour.
Add remaining 4 tablespoons of butter to the pan over medium heat and brown the chicken pieces evenly on both sides.
Cover the skillet, reduce heat and cook the chicken until tender about 10 minutes. Remove chicken and set aside.
Add wine to pan stirring and scraping to deglaze the pan. Bring to a boil and then boil 4 minutes to reduce the wine.
Stir in the cream and reduce sauce over medium heat – about 3 to 4 minutes.
Return Chicken and onions to the pan and simmer about 5 minutes.
Butter is used to sauté onions and brown chicken. Wine is used to deglaze pan (wine dissolves flavor components that water cannot). Boiling off the alcohol mellows the flavor and reduces possibility of alcohol curdling the cream.