If pork roast comes in netting or is tied, remove netting or strings. Remove fat from pork. In 10-inch skillet, heat oil over medium-high heat. Sprinkle salt and pepper over pork. Cook pork in oil about 10 minutes, turning occasionally, until brown on all sides.
In 4- to 5-quart slow cooker, place sweet potatoes, onion and garlic. Place pork on vegetables. Pour broth over pork.
Cover; cook on Low heat setting 8 to 10 hours.