In a large resealable plastic bag, combine the flour, onion powder and mustard. Add pork, one piece at a time, and shake to coat.
In a large skillet, brown pork in oil over medium-high heat.
Transfer to crock pot.
Pour broth over pork.
Cover and cook on low for 5-6 hours or until tender.
Remove pork and keep warm.
For gravy, pour 2-1/2 cups cooking juices into a large saucepan. Combine cornstarch and water until smooth; stir into juices. Bring to a boil; cook and stir for 2 minutes or until thickened.