In a large mixing bowl, combine rice flour, water, cornstarch, sugar, and salt. Mix well.
Let the batter rest for about 30 minutes.
Then, place a pot on the stove over medium heat and stir the mixture continuously in one direction.
After about 10 minutes, when the batter starts to thicken, add 1 tablespoon of cornstarch.
Add 1 tablespoon of cooking oil.
Continue stirring until the batter mixture thickens further and becomes heavy to stir, then remove the pot from the heat.
Lightly oil a mold to prevent sticking, and pour the batter into the mold.
Place the mold in a steamer and steam for about 30 minutes. Check if the batter is cooked by poking a chopstick into it; if the chopstick comes out clean without any white batter sticking to it, the batter is cooked.
Once cooked, remove the batter from the steamer and let it cool.
In a saucepot, combine water, sugar, soy sauce, and vinegar. Heat the mixture until the sugar dissolves and let it boil for about 1 minute, then turn off the heat.
Once the batter is completely cooled, cut it into bite-sized pieces.
Heat a pan on the stove, add about 5 tablespoons of cooking oil, and wait until the oil is hot before adding the batter pieces to fry.
Fry over medium heat for about 5 minutes until one side is golden brown, then flip and fry for another 3 minutes.
Then, remove some of the oil from the pan, leaving about 2 tablespoons. Add eggs and fry for about 2 minutes until the eggs are cooked, then sprinkle some chopped green onions on top to finish.
Serve the dish with some shredded green papaya, and drizzle sweet and sour dipping sauce over it to serve.