Place oil in wok and heat over medium heat. Add sausage and fry in a pan for 2 minutes.
Add dried shrimp and stir fry one additional minute. Add scallions and taro and fry for 3 minutes. Sprinkle it with salt, sesame oil and pepper powder.
Then add 2 ½ cups water so all ingredients are submerged. Cover wok with lid and heat ingredients over medium low heat allowing to simmer for 8 minutes. Uncover, turn off heat and allow to cool a bit.
Mix both types of rice flour in a large bowl with 1 ½ cups of water until smooth. Add taro mixture (it does not need to cool completely prior to being added). Stir until it forms a cement like paste.
Oil two 9-inch cake tins and divide the mixture evenly among the pans. Smooth out the mixture ensuring there are no air pockets.
Steam the pans in a double decker steamer for 45 minutes. Check at the half-way mark to make sure your steamer hasn’t run out of water. If it has, add more. If you don’t have a steamer, you will have to steam the pans individually. Once you are done steaming, insert a toothpick to ensure the cake is done.
Cool completely. Then you can freeze the taro cake in a Ziploc bag and store it for a later date. Alternately, you can put a few tablespoons of oil in a pan and fry the cake (after cutting) on each side until it is golden brown. Add salt and serve with a side of oyster sauce for dipping if desired.