In a very large skillet, heat the oil. Add the boar in a single layer and cook over moderately high heat, turning occasionally, until browned, about 10 minutes. A nice crust in the browning stage allows for great texture in the completed dish.
Transfer the boar to a large enameled cast-iron casserole or Dutch oven.
Add the garlic, star anise, cloves and cinnamon sticks to the skillet and cook over low heat, stirring occasionally, until fragrant, about 1 minute.
Add the water, soy sauce, kecap manis and sugar and scrape up any bits stuck to the pan.
Pour the liquid into the casserole and bring to a boil. Simmer over low heat, partially covered, until the meat is tender and nearly falling off the bone, about 2 hours; turn the shanks occasionally.
Transfer the boar to shallow bowls and strain the broth. Spoon off as much fat as possible.
Serve the boar with rice and cilantro and spoon some of the fragrant broth on top.