Cut the pork ribs down the bone to separate into single ribs. Line the ribs in baking trays on their side and as closely together as you see fit.
For the BBQ sauce, mix all remaining ingredients in a large bowl, whisking them all together to make a thickish sauce.
With the racks of ribs in their trays, ladle the sauce mixture over the ribs in as equal quantity as possible. Then cover the ribs with foil and place in a preheated 170 C / 150 C Fan / Gas 3 oven for 90 minutes.
Take ribs out of the oven and leave to cool with the foil still in place.
To finish on the BBQ:
Heat the BBQ to medium high heat. When the BBQ is ready, turn the ribs over in their trays, to let the sauce run back over the ribs as they cook. Recover trays with the foil.
Place the trays on the BBQ. Leave the ribs on the BBQ, in their trays and covered. When the sauce is bubbling, the ribs will be fall off the bone, succulent with an amazing taste of the sauce.
To finish in the oven:
Return ribs to oven, preheated to 180 C / 160 C Fan / Gas 4. Bake for 25 minutes, covered.