2) In a large resealable bag or nonreactive container, combine the vinegar, water, 1 tbsp of the salt, 1 tbsp of the pepper, four of the garlic cloves and the ribs. Leave to sit at room temperature for 15 minutes only.
3) Remove the ribs from the brine and season both sides with the remaining salt and pepper. Sear the ribs on the griddle until lightly browned.
4) In a large roasting pan fitted with a rack, arrange the ribs on the rack and pour in half the beer. Drink or discard the remaining beer. Add the onion and remaining garlic cloves.
5) Cover the pan tightly with aluminium foil and put into the hot oven. Reduce the heat to 150C/Gas 2 and roast the ribs for 1 1/2 hours. Remove the foil and baste the ribs with the BBQ sauce. Roast for 7 minutes, then turn the ribs over, baste again and roast for another 7 minutes.
6) Remove the ribs from the oven to a cutting board and slice between the ribs. Arrange on a serving platter and serve.
1) In a medium saucepan over medium-high heat, add the olive oil. When the oil is hot, add the onion and serrano and cook until the onion is translucent. Stir in the garlic and the ginger and cook for 1 to 2 minutes longer, being careful not to burn the mixture.
2) Deglaze the pan with the vinegar and then add the raspberries, jam and treacle. Stir to combine, then lower the heat and simmer for 15 minutes. Puree with an immersion blender, then strain through a sieve into a bowl or jar to remove the seeds, pushing the sauce through as much as possible.
Cook's Note: The BBQ sauce can be stored, covered, in the refrigerator for up to a week.