Soak the dried scallops and dried shrimp in water overnight. Drain the water. Use your hands to shred the scallops. Roughly chop the dried shrimp.
Heat 1 1/2 tablespoons of oil in a skillet (or sauté pan) over medium-high heat. Add the scallops, shrimp, Chinese sausage, and shallots and cook for about 2 minutes, stirring frequently. Add the oyster sauce, salt, and white pepper. Stir to combine. Turn off the heat and transfer everything to a bowl.
Trim the tops off the daikon and peel them. Grate the daikon into a 9×13 pan or a bowl. You are doing this to ensure that you save all the daikon juices that release as you are grating the turnips. Alternatively, grate the daikon using a food processor.
Heat 1 1/2 tablespoons oil in a large wok (or sauté pan) over medium-high heat. Add the shallots and garlic to the wok and sauté for about a minute, until fragrant. Transfer the grated daikon and daikon juices into the wok. Add 1 1/2 cups of water, the rock sugar, salt, chicken powder, white pepper, and garlic powder to the wok. Cover the wok with a lid and cook the daikon for about 5 minutes.
While the daikon is cooking, make the batter. Mix the rice flour and cornstarch in a mixing bowl. Add 1 cup of water to the flour and stir. The batter might be stiff at the beginning, but keep stirring until the batter is smooth.
Uncover the wok and turn off the heat. Dig out the pieces of garlic. You don’t want large chunks of garlic inside the cake. Add the stir fried shrimp, scallops, and Chinese sausage to the wok and stir to combine. Then, add the batter to the daikon and stir.
Lightly grease the cake pan with oil. Transfer all the ingredients from the wok to the cake pan. Use a spatula to smooth out the top of the turnip cake.
Wash the wok. Cover the wok with about 2 inches of water and bring it to boil. Place the steaming rack in the center of the wok. Make sure that the water level is just below the top of the steaming rack. Then, carefully place the turnip cake on top of the steaming rack. Cover the wok and cook for 28 to 30 minutes.
Uncover the wok. Because of condensation, you may notice some water on top of the steamed cake. That’s okay. Let the cake cool for 10 minutes on the steaming rack before removing from the wok. Carefully drain the water over the sink. Let the turnip cake cool completely before serving.
To pan fry the turnip cake, I usually chill my turnip cake overnight so that the cake stiffens. Slice the cake into small squares or rectangles. Heat 2 tablespoons of oil in a large skillet over medium-high heat. Add the turnip cake pieces and pan fry each side for about 4 minutes, until golden brown. Serve the turnip cake with chili oil or chili oil crisp.
My mom uses chicken powder often to enhance the umami flavor of her dishes. Feel free to leave it out. You can substitute the chicken powder with onion powder to give the dish more flavor.
You can use an 8×8-inch square pan or any pan that fits inside a wok.