To a large bowl add all ingredients except beef and stir.
Add the beef and stir, covering all of it with the mixture.

Tightly cover with cling film over the rim of the bowl and the surface of the beef.
Marinade in the fridge for at least 3 hours.

Preheat oven to 80 degrees celsius.
Drain the meat ontop of paper towels before transferring over onto a grill rack to put into the oven.
Cook the beef at 80 degrees celsius for 3 hours.

Wait for the beef to cool and cut into pieces with scissors.

Put into an air tight sealed bag, jar or tupperware box to store.