Place the onion, garlic, carrots, potatoes, and spices in the
cooker. (If your corned beef comes with a seasoning packet, you do have the option of using that instead of the spices listed here.) Rinse the corned beef brisket and add it to the cooker along with the beef stock. Place the dried split peas into a
pudding bag, or wrap them in the cheesecloth, tying the cheesecloth loosely so that the peas have room to expand. Push the bag down into the liquid, adding a cup or two of water to make sure everything is submerged. Cover and slow cook on LOW for 8 hours (or 4 hours on HIGH).