Place the paprika, cayenne pepper and black pepper into a bowl and mix
Rub into the brisket and then season with salt
Set aside for a day in the fridge
To cook
Preheat the oven to 160° Celsius
Remove the brisket from the fridge and place into a large lidded ovenproof casserole dish
Place the sugar, tomato paste, mustard, oil, soy sauce, Worcestershire sauce and beef stock into a bowl
Whisk to combine and then pour into the casserole dish, together with the lager
Put the lid on the dish and place into the oven to cook for 4 hours
Light your barbecue to be hot and ready when the 4 hours is up
Remove the brisket from the casserole and put the casserole onto the stove over a medium to high temperature
Leave the stock to reduce until it has thickened to coat the back of a spoon
When it has reduced, remove from the heat
In the meantime place the brisket onto the barbecue and cook for 10 minutes, turning to char on each side
Remove from the barbecue and place onto a chopping board
Use 2 forks to pull the meat apart and then place the meat into the sauce
Mix to coat the meat with the sauce and then return to the chopping board and serve
Notes
I cut baby potatoes in half and cooked them in the oven at the same time as the brisket. I added them halfway through the cooking process and then tossed them with fresh herbs to serve.