Place the pork slabs in a large sealable baggie.
Mix the marinade ingredients in a medium bowl.
Reserve ½ cup of the marinade for basting and set aside.
Pour the remaining marinade over the ribs.
Seal the bag and toss to ensure that the ribs are evenly coated.
Place the ribs into the refrigerator overnight.
Once they are marinated, remove the ribs from the bag and pat them dry. Discard the baggie and used marinade.
Prepare barbeque to 220°/104°C with indirect heat. Leave one side of the barbeque on high and the other side off. Insert a drip pan under the grates of the side that has no heat.
Place the pork over the drip pan.
Close lid adjust temperature if necessary to read 220°/104°
Slow cook the ribs for 3 hours or until tender.
Baste with the reserved sauce every 30 minutes.
Once done, remove the ribs from the barbeque and tent under tin foil for 20 minutes.
Cut between the bones and serve with your favourite plum sauce.