Chicken Chasseur

I love the sauce on this chicken!   This recipe is taken from Food & Wine Magazine's Quick from Scratch Chicken Cookbook. 

1 Tablespoon cooking oil
4 bone-in chicken breasts (about 2 1/4 pounds in all)
1 teaspoon salt
1/2 teaspoon fresh-ground black pepper
1 Tablespoon butter
1 onion, chopped
3/4 pound mushrooms, sliced
2 cloves garlic, minced
1 1/2 teaspoons flour
6 Tablespoons dry vermouth or dry white wine
2/3 cup canned low-sodium chicken broth or homemade stock
1 cup canned crushed tomatoes, drained
1/4 teaspoon dried thyme
2 Tablespoons chopped fresh parsley

1.  In a large, deep frying pan, heat the oil over moderately high heat.  Season the chicken with 1/4 teaspoon each of the salt and pepper and add to the pan.  Cook until browned, turning, about 8 minutes in all.  Remove.  Pour off all but 1 tablespoon fat from the pan.
2. Add the butter to the pan and reduce the heat to moderately low.  Add the onion and cook, stirring occasionally, until translucent, about 5 minutes.  Raise the heat to moderately high.  Add the mushrooms, garlic, and 1/4 teaspoon of the salt.  Cook, stirring frequently, until the vegetables are browned, about 5 minutes.
3.  Add the flour and cook, stirring, for 30 seconds.  Stir in the vermouth and bring back to a simmer.  Stir in the broth, tomatoes, thyme, and the remaining 1/2 teaspoon salt.  Add the chicken and any accumulated juices.  Reduce the heat; simmer, covered, until the chicken is done, about 10 minutes.  Stir in the parsley and the remaining 1/4 teaspoon pepper.