1) Preheat the oven to 125C/Gas 1/2. Put the ribs on a baking tray, season with salt and pepper and drizzle with olive oil.
2) Stick them in the oven, and let the ribs bake, low and slow for 1 1/2 hours.
3) Meanwhile, make the sauce. Wrap the bacon around the middle of the thyme sprigs and tie with kitchen twine so you have a nice bundle. Heat oil in a large saucepan over medium heat. Add the thyme bundle and cook slowly for 3 to 4 minutes to render the bacon fat and give the sauce a nice smoky taste. Add the onion and garlic and cook slowly, without coloring, for 5 minutes. Add all of the rest of the sauce ingredients, give the sauce a stir, and turn the heat down to low. Cook slowly for 20 minutes to meld the flavours.
4) Put some sauce in a separate bowl for basting, reserving the remaining sauce for serving.
5) Baste the ribs with the sauce and let them continue cooking, basting twice more, for 30 more minutes. When the ribs are cooked, take them out of the oven. You can let them hang out like this until you're ready to eat.
6) When ready to eat, preheat the grill for 5 minutes and grill the ribs, basting with the sauce. They should become crisp and charred, about 5 minutes on each side.
7) Pick the onion and garlic out of the sauce and serve with ribs.