Remove the outer plastic package the meat comes packaged in and place the meat in the slow cooker with the seasoning packet enclosed and the juice from the bag. Completely cover the meat with water. Secure the lid on the slow cooker. I set my slow cooker for ten hours on LOW the night before.
The next morning, grab a cutting board and chop the potatoes, carrots, and onions into thick wedges.
Add carrots, potatoes, and onions to the slow cooker. Set the slow cooker to cook for another 6 hours on HIGH.
Chop or slice the cabbage. I typically only use about 3/4 of the cabbage.
Cover the vegetables with the cabbage and set the slow cooker to cook for another 6 hours on HIGH. You may add more water, if needed.
After cooking the corned beef in the slow cooker or Instant Pot, remove the corned beef and place it in a greased baking pan.
Here is an awesome trick that makes the corned beef look and taste fabulous. Heat your oven to (350°F) = (176°C) and place just the corned beef on a greased shallow pan FAT side up. Lather the fat with mustard and sprinkle with 1/2 cup brown sugar.
Bake 20-30 minutes until the brown sugar looks crispy. This is absolutely the most tender recipe you will ever make. The meat will be 'fork tender' when finished cooking. Delicious! Serve immediately with vegetables.
PRESSURE Cooker Recipe:
*same ingredients as above*