In a bowl, combine the thinly sliced beef, soy sauce, oyster sauce, baking soda, cornstarch, granulated sugar and sesame oil.
Give it a good mix and let it sit in the fridge for at least 30 minutes.
Prepare the satay sauce:
In a bowl, combine sha cha sauce (Chinese BBQ sauce) peanut butter, soy sauce, sugar, lemongrass powder, curry powder, and water.
Mix together until smooth and incorporated.
Set aside.
Cook:
In a large frying pan over medium heat, add in the vegetable oil, shallot, and garlic.
Sauté for a few minutes, until slightly fragrant.
Add in the marinated beef slices and continue to cook, for another 3-4 minutes, until no longer pink.
Pour the satay sauce over the beef and continue to cook, coating the beef with the sauce. If the sauce appears too thick, add a little more water.
Remove from heat.
Prepare the noodles:
Cook the noodles according to the package directions.
Drain the noodles and rinse under cold water. Drain thoroughly.
Assemble:
Add about ½ package of seasoning to each serving bowl, pour in hot boiling water and stir to dissolve (use more or less water according to your preference). If using broth: warm up chicken broth/beef broth in a small saucepan adding to the bowls.
Divide the noodles into serving bowls and top with satay beef.