Preheat the oven to 300°. On a rimmed baking sheet, season the ribs with salt, pepper and garlic. Drizzle with oil and scatter the cloves over the ribs and in the pan. Pour the beer over the ribs, cover with foil and bake for 2 hours, until the meat is tender.
2. Strain the pan juices into a saucepan. Whisk in the ketchup, jam and lemon juice and boil over high heat until reduced to 1 1/2 cups, about 20 minutes.
3. Preheat the broiler. Set the ribs meaty side down on the baking sheet, brush with glaze and broil 4 inches from the heat for 7 minutes. Turn the ribs and brush with half of the remaining glaze. Broil for 10 minutes, until starting to char. Brush with the remaining glaze and broil until browned, 10 minutes. Let rest for 10 minutes and serve.