With the rack in the middle position, preheat the oven to 375°F (190°C).
In a 13 x 9-inch (33 x 23 cm) glass baking dish, coat the duck legs with the pickling spice. Season with salt and pepper. Arrange the duck legs skin side up and cover the baking dish with foil.
Bake for 1 hour 30 minutes or until the meat starts to detach from the bone.
Meanwhile, in a pot over medium heat, soften the onion and garlic in the oil. Add the remaining ingredients. Bring to a boil and simmer over low heat for 20 minutes. Season with salt and pepper.
Remove the foil. Using a spoon, remove the fat from the baking dish. Pour the fruit ketchup over the duck. Return to the oven and cook, uncovered, for 30 minutes, basting occasionally with the sauce.
Serve the duck legs with the fruit ketchup, fresh herb and garlic roasted potatoes (see recipe) and a green salad, if desired.
Brome Lake is the most common brand of Pekin duck available in grocery stores. You can also use Barbary duck, most often found under the Canard Goulu brand. Since Barbary ducks are larger, cook them for 30 minutes longer at step 3.