Preheat your oven to 300°F (150°C).
Rinse the corned beef brisket under cold water.
Pat the brisket dry with paper towels.
Rub the brisket with crushed mustard seeds, black peppercorns, and coriander seeds.
Place the brisket in a roasting pan, fat side up, and add minced garlic around it.
Pour beef broth into the bottom of the pan.
Cover the roasting pan tightly with foil and bake for 3 hours.
Remove the foil and increase the oven temperature to 400°F (200°C).
Roast for an additional 30-45 minutes, basting occasionally.
Let the brisket rest before slicing it.
Slice against the grain and serve with garnished parsley.