Preheat the oven: preheat the oven to 180°C / 350-375°F / Gas Mark 4-5.
Dry rub: add the mustard powder, garlic powder, onion powder, paprika, cayenne pepper, salt and cracked black pepper to a small glass jug and whisk to combine.
Liquids: add the Worcestershire sauce, apple cider vinegar and water to a mixing jug and use a teaspoon to stir to combine.
Pork: remove pork from fridge, take out of packaging, cut off any binding string and pat dry with paper towel.
Season: place the pork onto a chopping board, top side facing down. Pour half of the dry rub over the top and massage the rub all over the side of pork. Flip to the top side and repeat, also covering the sides and edges of the pork with the rub.
Dutch oven: spray base and sides of Dutch Oven with olive oil spray. Pour combined liquids into the base of the bowl. Gently pick up the seasoned pork and place it into the Dutch Oven. Put the lid on top and place on the middle shelf in the preheated oven. Cook for 3 hours.
Cooked pork: when the 3 hours are up, use oven mits to remove the pork from the oven. Place onto a heatproof surface. Remove the lid and let the pork rest for 4 to 5 minutes.
Grill/broil: change the oven setting to grill at 200°C 392°F6.
Baste and grill: lift the cooked pork up and out of the Dutch Oven (Don't discard liquids in Dutch Oven or rinse at this stage). Place in the centre of a silicon lined baking mat. Use a pastry brush to liberally baste the cooked pork with the BBQ sauce. Place into the oven and grill for 10 minutes. Remove and repeat the basting process followed by a further 10 minute grill period.
Pull: use oven mits to remove the grilled pork from the oven. Use 2 pairs of tongs to transfer to a chopping board. Initially use a knife to cut the pork, then use a fork in each hand to pull (shred) the pork into pieces.
Barbecue sauce: add the pulled pork back to the Dutch Oven, pour in 2 tablespoons of BBQ sauce and use a wooden spoon to stir and combine.
Serve: use for burger fillings, in hot dog buns, as sandwich fillings, as a pizza topping, for slides, salad, nachos or tacos.