Preheat the grill to 350°F.
Grease a large cast iron skillet with 1 tablespoon of butter, set aside.
Cook the pasta in a large pot of boiling water, about 10 minutes. Drain and set aside.
In a large saucepan, melt 6 tablespoons of butter over medium heat. Add the flour, and cook while stirring constantly for 3 minutes.
Using a whisk, add the milk in slowly. Cook for an additional 4 minutes, until thickened.
Remove the pan from the heat, add in 1 tablespoon of Weber® Roasted Garlic & Herb Seasoning and 2 cups of the cheese, stir well to incorporate.
Add the pasta and brisket, and mix together well. Pour into skillet.
Mix the remaining cheese, bread crumbs, and 1 tablespoon of Weber® Roasted Garlic & Herb Seasoning in a bowl. Sprinkle evenly over the skillet.
Place on grill and cook until golden brown and bubbly, 20-30 minutes.
Divide evenly between the 4 toasted buns. Drizzle with Weber® Sweet & Thick Original BBQ Sauce, top with the remaining buns, and serve!