Preheat the oven to 325 degrees F. Lay ribs meaty side up in a single layer in a baking dish. Season with salt and pepper. Pour in the stock. Cover and bake for 90 minutes. Meanwhile, heat the oil for the sauce in a pot over medium-high heat. Add the onion, bell pepper, garlic and ginger and cook 2-3 minutes. Add the remaining ingredients and stir and cook until well-combined, about 3-4 minutes. Remove from the heat. When the ribs have cooked 90 minutes, drain and discard the liquid from the pan. Pour over the sweet and sour sauce. Cover and bake the ribs 20 minutes more. Transfer rib to a serving platter, spoon over the sauce and serve.