Use a 6-quart slow cooker. Place the cut sweet potatoes into the bottom of the slow cooker. In a large mixing bowl, combine the cubed pork, apricot marmalade, onion flakes, soy sauce, and ground mustard. Pour this mixture on top of the sweet potatoes. Add in the entire bag of frozen mixed vegetables (no need to thaw).
Cover and cook on low for 6-8 hours, or on high for 4-5 hours, or until the pork is tender and no longer pink.