Marinate the pork slices. Put in half of the oyster sauce, fish sauce, soy sauce, and cornstarch. Stir well. Set aside for 5 minutes.
Pour in oil in the wok. Set the stove to medium heat. Wait until it is hot enough, you can see smoke coming out. Throw in crushed garlic. Stir fry until it is golden. I like to take out the garlic.
Throw in the marinated pork slices. Stir fry until they change color. Add in the broccoli, stir fry altogether for a few minutes.
Pour in the remaining seasoning: oyster sauce, fish sauce, soy sauce. Add Shaoxing wine. Throw in mushroom powder and pour some water. You can cover with the sauce pan lid for 2 minutes. This will cook the broccoli and still keep it green and crunchy.
Add in the remaining cornstarch slurry to make the broth thicker. Stir fry for a few more minutes until the broth thickens. If you like it lighter, pour some more water. Stir fry for a while, turn off the stove, serve on a plate.
Video
Notes
You can blanch the broccoli with hot water for 1 minute, this will make the cooking process in the wok faster. If you don't, it is okay to just stir fry it in the wok. Just use the sauce pan lid to cover for 2 minutes.
Cornstarch will help make the meat soft and velvety just like you have in Chinese restaurants. Cover the meat slices with cornstarch and other seasonings like oyster sauce, soy sauce, and water. Marinate for 5 minutes.
Shaoxing wine or Chinese cooking wine balances the flavor in the dish. Pour in just after you throw in the vegetables in stir fry dish.