Set an oven rack 6" beneath the broiler. Set the broiler to high. Place the ribs, meaty side up, on a non-stick baking sheet. Sprinkle with salt, pepper and paprika. Broil 3 to 4 minutes, or until richly browned. Turn the ribs over and cook 2 to 3 minutes. Remove ribs from the oven.
In your slow cooker, combine the sauerkraut, onion, celery, carrot, garlic and sage and mix well. Nestle the ribs into the sauerkraut; pour in the stock. Cover and cook on the low setting for 6 to 8 hours.
Divide the sauerkraut, vegetables and ribs among 4 plates, sprinkle with parsley, and serve.
Note: This recipe is designed for an oval-shaped slow cooker with a 5 litre or more capacity.