Pat the brisket dry with paper towels. Rub the olive oil evenly over both sides. In a small bowl combine kosher salt, black pepper, garlic powder, and smoked paprika; sprinkle and rub the spice mix over the brisket so it is evenly coated.

Braise or Roast

Preheat oven to 300°F (150°C). Place the brisket fat-side up in a roasting pan or Dutch oven. Pour 1 cup beef stock or water into the pan (not over the brisket) to keep the environment moist. Cover tightly with lid or foil and roast for 2 to 2 1/2 hours or until fork-tender (internal temperature about 195–205°F). Check after 90 minutes: if liquid has mostly evaporated, add a few tablespoons more.

Rest and Slice

Remove the brisket from the oven and let rest, covered, for 15–20 minutes. Transfer to a cutting board and slice thinly across the grain into 1/8–1/4-inch slices. Reserve juices for finishing if desired.

Smoked Sausage

Prepare Glaze

While the brisket rests (or during the last 20 minutes of brisket cooking), mix yellow mustard, brown sugar, apple cider vinegar, and black pepper in a small bowl until smooth.

Warm and Glaze

Heat a large skillet over medium heat. Place the halved sausage cut-side down and cook 2–3 minutes to color. Reduce heat to medium-low, brush the mustard glaze over cut sides and turn sausages to glaze all sides, cooking a further 3–4 minutes until heated through and glaze slightly caramelizes. Alternatively, place sausages on a baking sheet under a broiler and brush glaze; broil 2–3 minutes per side, watching closely.

Combo Finish & Serving

Combine and Sauce: Arrange sliced brisket and glazed sausage on a serving platter or assemble into rolls. Warm the barbecue sauce briefly (microwave 20–30 seconds or heat in a small pan) and brush or drizzle over both meats. If you reserved brisket juices, whisk a tablespoon into the barbecue sauce for extra flavor.

Serve: Sprinkle chopped parsley over the meats, add pickles or pickled onions on the side, and serve on rolls or plates. This recipe yields about 4 generous servings. Leftovers keep in the refrigerator for up to 3 days.