In a large bowl, mix rice flour, cornstarch, wheat starch, salt oil and water. Stir well to make sure the batter is well mixed. Set aside for 10 minutes.

Prepare a rectangle or square pan and a large wok that can hold the pan. Bring enough water to a boiling and then place your pan in.

In a small bowl, pour a small amount of oil and then brush the steaming pan with a very very thin layer of oil and then pour the batter in. (I pour around 3 tablespoons of batter each time and it should spread to form a very thin layer at the bottom). Make it even and then steam for 1 minute until the batter firms, then sprinkle shrimp and green onions. Re-steam for 2 minutes over high fire.

Transfer out, use a knife to separate the edges from the pan firstly and then roll it up to a 2-3cm wide tube. If you prefer, you can cut the tube into one-bite size sections.

In a saucepan, add all the ingredients expect sesame oil and heat to boil. Then turn down the heat and let it simmer for 3-5 minutes. Add sesame oil and ransfer out to cool down.

Garnish toasted white sesame seeds and chopped green onions. Drizzle the sauce and top with sha cha sauce (totally optional, but I recommend you trying it.)