Use a large mixing bowl to mix all the ingredients in Prep B. Start with the dry ingredients first, then add the wet. Stir the contents until it becomes a milky white slurry solution.
Heat a deep nonstick wok or pot (not pan) with the oil from Prep A on medium high heat. When the oil is hot, add the diced taro, and fry the pieces evenly until it is fragrant (about 5 minutes).
At this point, some of the starch sediments would have collected at the bottom of the Prep B mixing bowl. Give it another mix, and make sure the solution is evenly mixed throughout (use your hands to mix if you have to).
Add the Prep B ingredients into the pot or wok where the taro has been frying. Continue cooking and heating the mixture on medium heat. Stir constantly, until the starch mixture thickens into a chowder-like consistency. (About 10-15 minutes) Continue to cook the mixture until it feels like a batter, then turn the stove off.
Grease two 2-quart glass baking dishes with some vegetable oil, and pour your taro rice cake batter into the dishes. Make sure you divide them evenly. Smooth over the top of the batter.
Put a Chinese wire steaming rack into a clean wok or deep pot. Add tap water, until the water is level with the steaming rack or stand. Close the lid, and turn the stove on high. Bring the water to a steaming boil. You should see steam escaping on the sides of the lid.(The water should have come to vigorous, rolling boil)
Open the lid and set it down. With both hands, carefully place one of the baking dishes with the taro cake batter onto the steaming rack. Close the lid, and steam on high for 30 minutes.
As the steam escapes, the water will evaporate. Make sure you check the water level, and add more if necessary. (I added water into the wok every 7-10 minutes).
After 30 minutes, transfer the dish out onto a trivet using kitchen mitts, and place the other dish in. Repeat and steam the second dish on high for 30 minutes, adding water when needed. (Tip: If you see don't see much steam coming out from the side of the lid, you need more water).
When done, remove the second dish, and turn off the stove.
Cool your dish completely. If there is steam water collected inside the dish, drain the water before storing your cakes in the fridge. To store, cover the cakes with plastic wrap, put on the Pyrex covers, and place it in the fridge overnight.