Rinse the corned beef brisket under cold water
Place the brisket in a large pot or Dutch oven
Add enough water to cover the brisket
Add the spice packet if included
Add optional aromatics such as onion, garlic, bay leaves, and peppercorns
Bring the water to a boil
Reduce to a low simmer
Cover and cook until tender
Simmer about 50 to 60 minutes per pound
Check occasionally and add more water if needed to keep the brisket covered
Test for tenderness with a fork
Remove the brisket from the pot
Let the brisket rest for 10 to 15 minutes
Slice the brisket against the grain
Serve with cooked vegetables if desired