Combine kosher salt and baking powder together and sprinkle over shrimp. Mix well, and set aside. This can be done up to a couple of hours beforehand.
Prepare Sauce
Combine one third of the garlic, oyster sauce, soy sauce, white pepper, sesame oil, cornstarch, and the 2 cups of chicken stock. Stir to combine. Set aside for now.
Bok Choy
Trim ends of Bok Choy, and separate outer leaves. Rinse Bok Choy and dry in a salad spinner.
Heat 2 tablespoons of vegetable oil in a wok or stir fry pan over medium heat. Add ⅓ of the garlic and cook until the garlic begins to brown.
Add the bok choy, and stir to coat. Once the Bok Choy begins to wilt, and the remaining 2 tablespoons of chicken stock. If your pan has a cover, use it.
Stir the Bok Choy after a minute. Continue to cook the Bok Choy stirring occasionally until the leaves are wilted but the ends are still crunchy. About 5 minutes total.
Once cooked, remove the Bok Choy from the pan and set aside.
Shrimp
Add the remaining oil to the pan and once heated, add the shrimp. Try to spread shrimp into a single layer as possible.
Once shrimp begin to brown, flip them over and allow the other side to cook. Depending on the heat, it may only take 3 to 4 minutes per side.
Once the shrimp begin to turn pink, add the remaining garlic.
Stir the shrimp and garlic frequently and cook until the garlic begins to brown and becomes fragrant. Maybe another minute.
Remove the shrimp from the pan and set them aside.
Putting it all together:
Add the sauce to the pan and cook until it begins to simmer.
Once it is simmering, continue to cook until it reaches the desired consistency. (I like it to be able to coat the back of a spoon.)
Once it reaches the desired consistency, and back the shrimp.
Stir the shrimp into the sauce and bring it back to a simmer.
Once simmering, and the Bok Choy and stir to combine.
Bring back to a simmer and then remove from the heat.
Once simmering, transfer contents to a bowl to serve.