Preparation:

Mix garlic and vegetable oil in a small bowl and Set aside for 1 hour.

Preheat oven to 225 degrees F (110 degrees C).

Combine black pepper, paprika, coriander, dry mustard, white pepper, and cayenne pepper in a large bowl and set aside.

Cover a baking sheet with a large sheet of heavy-duty aluminum foil large enough to completely wrap the corned beef brisket. Coat aluminum foil with prepared garlic oil. Lay brisket on foil and brush with remaining garlic oil. Cover all sides of corned beef brisket completely with pepper mixture, saving 1 to 2 tablespoons.

With fat side of corned beef brisket up, wrap in the sheet of aluminum foil. Place wrapped corned beef on another sheet of aluminum foil (again, large enough to completely wrap brisket) with the seam and fat side down. Place double-wrapped corned beef on a third sheet of aluminum foil, same as before (seam down), and wrap again.

Bake in the preheated oven for 6 hours. Allow brisket to cool to room temperature, about 3 hours. With the brisket still wrapped in aluminum foil, place on a plate and refrigerate between 8 to 10 hours.

Preheat the oven's broiler. Line a baking sheet with aluminum foil and place unwrapped brisket on the prepared baking sheet. Sprinkle top with 1 to 2 tablespoons of remaining pepper mixture. Place brisket in the oven about 6 to 8 inches below broiler heat. Broil briefly to brown surface, about 3 to 4 minutes. Remove brisket from the oven and slice to your preference.

Heat a large skillet over low heat. Heat brisket slices in the skillet with a few drops of water until fat begins to turn from white to translucent, about 5 minutes.

Alternative:

Place brisket into over about 10 inches from broiler and heat until brouwned. Flip to brown underside of brisket. Slice and serve hot from oven..