Step 1: Prepare the Corned Beef. Unwrap your corned beef brisket. If it came with a spice packet, sprinkle the contents generously over the top of the brisket. If not, you can make your own with 1 teaspoon each of black peppercorns, mustard seeds, and coriander seeds, plus 2-3 bay leaves.
Step 2: Arrange in the Slow Cooker. Place the corned beef brisket fat-side up in your slow cooker. Adding it fat-side up allows the fat to render down over the meat as it cooks, keeping it moist and adding incredible flavor.
Step 3: Add Liquids and Aromatics. Pour enough beef broth or water (or a mix of both) into the slow cooker to cover about two-thirds of the brisket. You can also add a splash of Guinness or hard cider for extra depth of flavor if you like. Add any additional aromatics like a quartered onion or a few cloves of garlic if desired.
Step 4: Cook the Beef. Cover the slow cooker and cook on LOW for 6-8 hours or on HIGH for 3-4 hours, until the corned beef is fork-tender. The exact time will depend on the size of your brisket and the efficiency of your slow cooker.
Step 5: Add Vegetables. About 2-3 hours before the beef is done (if cooking on low) or 1-1.5 hours (if cooking on high), add the chopped potatoes and carrots to the slow cooker, submerging them in the liquid as much as possible. Continue cooking until the vegetables are tender.
Step 6: Add Cabbage. During the last 30-60 minutes of cooking, add the large cabbage wedges to the slow cooker. Gently push them down into the liquid and around the beef and other vegetables. Be careful not to overcrowd the pot. Cook until the cabbage is tender-crisp.
Step 7: Rest and Serve. Once cooked, carefully remove the corned beef from the slow cooker and let it rest on a cutting board, covered loosely with foil, for 10-15 minutes before slicing against the grain. This resting period is crucial for juicy results. While the beef rests, you can remove the vegetables from the slow cooker. Slice the corned beef and serve with the tender vegetables and a drizzle of the flavorful cooking liquid. A dollop of Dijon mustard or horseradish sauce is the perfect accompaniment to this delicious Corned Beef and Cabbage Slow Cooker Recipe.