In a large skillet heat the butter, add the chicken and brown on all sides. Remove chicken and keep hot.
Add the onion to the skillet and cook slowly, stirring occasionally, 3 to 4 minutes. Add the flour and garlic and, stirring with a wire whisk, add the wine and broth and cook until the mixture is thickened and smooth.
Add the canned tomatoes, salt and pepper. Return the chicken to the skillet, cover and simmer until tender, about thirty minutes.
Remove the chicken from the skillet to a warm serving platter and keep hot. Add the fresh tomatoes to the skillet and simmer 15 minutes.
Pour the sauce over the chicken and serve sprinkled with chopped parsley.