Place the potatoes and carrots in the bottom of a 6-quart or larger slow cooker. Generously season the pork loin all over with salt and pepper. Place in the slow cooker on top of the vegetables.
Place the honey, vinegar, broth, and cornstarch in a medium bowl and whisk until smooth. Pour over the pork loin.
Cook until an instant-read thermometer inserted into the middle of the pork loin registers 155°F, 5 to 6 hours on the LOW setting or 3 to 3 1/2 hours on the high setting. Slice the pork loin and serve with the vegetables and sauce.
