For the sauce, mix all the ingredients for the sauce for oyster in a small bowl and set aside.
To prepare the oyster, place the thawed oyster in a colander and rinse with cold water. Drain well and coat the oysters in potato starch.
To cook the oyster, heat a frying pan over medium heat until you start seeing a small whisp of smoke. Once the pan starts smoking, add oil and swirl the pan to coat surface. Add the oysters and cook until the edge is crispy and golden brown.
Add the mixed sauce from Step 1, cook and stir until the sauce is thickened and transparent (If you are using large oysters, cover with lid and steam for about 1-2 minutes, until the inside is fully cooked).
Turn off the heat and add lettuce leaves. Stir well, then cover with lid to cook with residual heat. Do not cook too long, or the lettuce will get soggy.
In a large pot, boil the noodles in plenty of boiling water.
To make the soup, boil 1 ½ cups water in a small pot and add Premium Vegetarian Shoyu Soup Base.
Please the noodles in a bowl and top with oysters and lettuce. Pour the soup, and you are done!