1. The day before or a few hours ahead, preheat the oven to 180˚C. Place the onion, garlic, sugar, smoked paprika, thyme, stock, tomato puree, half of the smoky barbecue sauce and water in a large saucepan over high heat and bring to the boil.
2. Place the ribs in a roasting tray and pour the hot liquid over the ribs. Cover with foil and place in the oven for 40-45 minutes until the ribs are tender. Remove from the oven and leave to cool for 30 minutes or until ready to use (if using the next day place in the fridge when cooled covered with cling film).
3. Preheat the barbecue over medium heat.
4. Lift the ribs from the cooking liquid onto a board. Brush the remaining barbecue sauce evenly over the ribs to coat.
5. Place the ribs on the barbecue over indirect heat if you can and grill for 20 minutes, brushing with the marinade every 5 minutes, or until golden and sticky.
6. Serve with your favourite sides .