In a large resealable plastic bag, combine 1/4 cup flour, salt and pepper. Add pork chops, one at a time, and shake to coat.
In a large skillet, brown chops in oil over medium-high heat for 3-4 minutes on each side. Remove and set aside. In the same skillet, sauté mushrooms and garlic for 3 minutes. Add broth and rosemary; bring to a boil. reduce heat; to low; return pork to pan
Cover and simmer for 1 hour or until meat is very tender. Remove pork and keep warm. In a small bowl, combine the half-and-half, sour cream, mustard and remaining flour until smooth. Pour into skillet. Bring to a boil; cook and stir for 2 minutes or until thickened. Serve over pork chops.