Cooking a corned beef brisket: Start by bringing water to a boil in a large pot. When water comes to a boil remove the corned beef from its package and add to the pot (also add any juices from the package for the most flavor). Reduce the heat until the water is at a simmer (not a boil). Simmer for 3-4 hours until fork tender. If you are using a large enough stock pot and intend to add potatoes, carrots, and cabbage, do so for the last 30 minutes of the cooking time. Carving directions: Slice corned beef in thin diagoal slices across the grain at a slanting angle beginning at any point.