Place ribs in large frying pan or roasting pan. Cover with lightly salted water and bring to a boil. Reduce heat to low and simmer for 1 hour, or until meat is tender but not quite falling off the bone. Remove from heat, and drain.
While the ribs are simmering, melt butter in a saucepan over medium heat. Cook the onion and garlic until the onion softens. Remove from the heat.
In a blender, combine vinegar, water, tomato sauce, barbecue sauce and lemon juice. Pour in the melted butter mixture and purée for 1 minute.
Pour into the saucepan, and season with salt and pepper. Bring to a boil then remove from heat.
Place the cooked ribs in a roasting pan and mix with the sauce. Cover and refrigerate for at least 2 hours, up to overnight.
Preheat barbecue for medium-high heat.
Brush the grill hotplate with oil. Cook ribs for 10 to 20 minutes or until well browned, basting with sauce and turning frequently.
If you like your spare ribs spicy, add Tabasco sauce or chilli flakes to taste.
Made it vegetarian.
I've made ribs using this method a couple of times since finding the recipe. I've found that for really tender ribs they need to simmer more than an hour - our best yet were simmered for 2.5 hours at a very low simmer and then covered and put in the fridge to cool in the cooking water until we were ready to cook. While the sauce which accompanies the recipe is good, I've found that we actually prefer our favourite bottled BBQ sauce. It's just as good and much easier. I barbecue the ribs until heated thorough and then brush on the sauce during the last few minutes to prevent the sauce from burning. These are great for making ahead and require so little effort that they are definately a keeper. - 29 Sep 2008