- BRISKET AND GRAVY:
- 1 brisket, 8 to 9 pounds, cut into 2 equal parts
- 4 garlic cloves, sliced
- 2 teaspoons salt
- 3/4 teaspoon cayenne
- 2 tablespoons Rustic Rub 
- 2 tablespoons vegetable oil
- 4 cups thinly sliced onions
- 1/4 teaspoon freshly ground black pepper
- 2 cans (12 ounces each) beer
- 1 cup water
- HORSERADISH SAUCE:
- 2 cups pan gravy
- 2 tablespoons prepared horseradish
- 1/4 cup heavy cream
- Preheat the oven to 400?F.
- With a sharp pointed knife, make about 10 slits in each of the brisket pieces. Stuff each hole with 2 to 3 slices of the garlic. Season the meat with 1 teaspoon of the salt, 1/2 teaspoon of the cayenne, and the rub. Heat the oil in a large skillet over high heat and sear the meat evenly, 2 to 3 minutes on all sides. Transfer the meat to a large lidded Dutch oven. The meat can overlap. Bake, uncovered, for about 45 minutes. Remove the pot from the oven.
- In a mixing bowl, toss the onions with the remaining 1 teaspoon salt, remaining 1/4 teaspoon of the cayenne, and the black pepper. Arrange the onions around the meat in the roasting pot. Add the beer and water. Cover. Return the pot to the oven and reduce the heat to 350?F. Bake for about 2 1/2 hours, or until tender. Turn the meat over twice during the baking time.
- Remove from the oven and let cool for about 15 minutes. Transfer the meat to a cutting board and keep warm. Reserve the pan gravy.
- Mix together the gravy, horseradish, and cream in a saucepan over medium heat. Cook, stirring occasionally, for 4 to 5 minutes.
- To serve, thinly slice the meat and return to the gravy in the pot. Pour the horseradish sauce over the top of the meat and serve from the pot.