In a large bowl, combine the corned beef, finely chopped onion, minced garlic, and minced ginger. Mix well.
In a large skillet, heat the vegetable oil over medium heat.
Add the corned beef mixture to the skillet and cook for about 5-7 minutes, stirring occasionally, until the onions are translucent and the mixture is heated through.
In a separate bowl, combine the coconut milk and water. Mix well.
Season with salt and black pepper to taste.
If using banana leaves, cut them into large squares and wilt them over an open flame or in hot water to make them pliable.
Place a few taro leaves (or substitute leaves) in the center of each banana leaf square.
Spoon a portion of the corned beef mixture onto the taro leaves.
Fold the taro leaves over the corned beef to enclose it.
Pour a generous amount of the coconut milk mixture over the taro leaf bundle.
Wrap the banana leaf around the taro leaf bundle to form a secure package. If not using banana leaves, simply fold the taro leaves over the corned beef tightly.
Place the wrapped bundles in a steamer or a large pot with a steamer rack.
Steam the bundles over medium heat for about 1 to 1.5 hours, or until the taro leaves are tender and the flavors are well combined.
Carefully remove the bundles from the steamer.
Enjoy your meal!