Chicken Marsala

1 lb chicken breast halves
5 Tb Flour
1/4 tsp Salt
3 Tb Butter
1 small Onion finely chopped
1 pkg thinly sliced mushrooms
1 1/3 Cup Chicken Broth
1/8 tsp dried Thyme leaves

Combine 4 Tb Flour, Salt and Pepper. Dip chicken in flour until evenly coated.
Melt 2 Tb Butter in a skillet over medium heat and cook chicken. Remove to a platter and keep warm.
Melt 1 Tb Butter in same skillet over medium heat and cook the onion and mushrooms, stirring occasionally 3 minutes or until tender. Sprinkle with remaining 1 Tb Flour and cook, stirring constantly 1 minute. Add Broth and Thyme, scraping brown bits from bottom of pan and bring to a boil over high heat. Continue boiling, stirring frequently 2 minutes or until sauce is thickened. To serve, pour over chicken.