Sprinkle the top of the brisket with pickling spice, pressing it into the meat.
Put potatoes, carrots, onion, bay leaf and thyme into the slow cooker and put the brisket on top of them
Pour the water and beer over everything.
Cover and cook on low 5 hours.
Add the cabbage to the slow cooker, cover and cook for another hour, or until meat and vegetables are very tender.
Transfer the meat to a cutting board and slice.
Serve with the vegetables, and dijon, or grainy mustard.
Sometimes corned beef briskets are sold already dressed with pickling spice, or with a spice packet included. If this the case for you, omit the pickling spice in the recipe.
Slow cookers vary greatly from model to model. My Breville slow cooker cooks quite hot, even on low, and the cooking time for this recipe is based on that. You may need a longer or shorter cooking time depending on your own slow cooker.
The beer in this recipe is optional, but it does add flavour, especially if you use a Guinness stout. You can replace the beer with water, if you prefer.
Using a gluten-free beer, or omitting the beer will make this recipe gluten-free.