Combine the tomato paste, Worcestershire sauce, red pepper flakes and paprika in a 5-to-6-quart slow cooker. Add the ham, beans, bay leaf and thyme. Pour in 4 cups water; cover and cook on low, undisturbed, 8 hours.
Pour the tomatoes into a bowl and crush them with your hands. Add the tomatoes and their juices, the scallions and garlic to the slow cooker. Cover and cook 30 more minutes.
Remove the ham from the slow cooker and transfer to a cutting board to cool slightly before slicing. Set aside about one-third of the ham and 3 cups of the stewed bean mixture to make Ham Jambalaya. Serve the remaining ham with the bean mixture.