Prepare 2 cups of cooked white rice for later use.
Bring a couple cups of water to boil, cook the shaved beef in the boiling water for about 1 minute until the color of the beef has just changed, fish the beef out, set aside.
Whisk oyster sauce, soy sauce, cooking wine and sugar in a small bowl, set aside.
Add oil to the skillet, stir fry ginger slices over medium to medium-high heat for 1-2 minutes until fragrant, add onion slices and stir fry another 3-4 minutes until browned and soft.
Add the shaved beef into the pan, stir fry for about 1 minute.
Spread the sauce made in step 3 evenly over beef and onion, simmer for 4-5 minutes until the sauce has thickened.