1/4 cup brown sugar
1 tablespoon chile powder
1 tablespoon paprika
2 teaspoons garlic powder
2 teaspoons kosher salt
1 teaspoon freshly ground black pepper
1 teaspoon cayenne pepper
1 (5 pound) brisket
2 onions, sliced
1 cup beer
1 bottle good barbecue sauce
Stir together the brown sugar, chile powder, paprika, garlic powder, salt, black pepper and cayenne in a small bowl. Rub the mixture all over the brisket. Cover and refrigerate for several hours or preferably overnight.
Preheat the oven to 300 degrees F.
Place onions in a large roasting pan. Put the brisket top of the onions. Cover tightly with aluminum foil and roast until fork-tender and falling apart, about 3 ½ – 4 ½ hours. Remove the brisket from the pan and set it on a cutting board. Pour off most of the cooking liquid. When cool enough to handle, shred the meat with two forks and return it to the pan.
In a saucepan place a 1/2 cup water, beer, and bbq same and heat over medium-high heat. Bring to a boil, then reduce heat to simmer, and cook for 15 minutes or until sauce is thick and reduced a bit. Pour sauce over the shredded beef. Rewarm.
Serve brisket warm with sauce in lettuce cups, on hamburger or slider buns, or over mashed potatoes.