Place corned beef roast, fat side up into a crock pot. I like to use an oval shaped one so it can all lay flat.
Rub the seasoning packet, black pepper, and coriander over the top of the roast.
Add vinegar, water, thyme and bay leaves to the crockpot around the roast, careful to not displace all of the seasonings.
Cook on low for 8 hours or high for 4 hours until meat is tender and comes apart easily.
Serve over a bed of cabbage and enjoy!
It's okay to skip the extra coriander if you don't have any handy. I just think there isn't enough in the packet that comes with it!