Lightly coat 3-1/2- or 4-quart slow cooker with cooking spray. In a large bowl combine coleslaw mix, ground pork, bok choy, sweet peppers, onion, celery, green onions, salt, black pepper, and red miso. Place mixture in slow cooker.
In a medium bowl whisk together broth, soy sauce, tomato paste, sake, rice vinegar, and thyme. Pour broth mixture over pork mixture in slow cooker; stir to combine.
Cover and cook on low-heat setting for 6 hours or on high-heat setting for 3 hours.