Cut the chicken skin into 5 mm wide strips, and slice the garlic. Cut the shiitake mushrooms into 5 mm strips. Cut the ong choy (Chinese water spinach) into 4 cm lengths, and separate the stems from the leaves.
Heat a frying pan over medium high heat, and add the chicken skin. (No need for vegetable oil.) If a large amount of oil comes out from the skin while stir-frying, wipe it off with a paper towel.
When cooked through, add the garlic, shiitake mushrooms, and stems of ong choy (Chinese water spinach), and continue stir-frying for about 30 seconds.
Add the ong choy leaves, and season with salt and pepper. Add the oyster sauce, and stir-fry briefly. When cooked through, serve on a plate, and done!
Story Behind this Recipe
I kept the chicken skin in the freezer because I didn't want to waste it. I just tried using it in a stir-fry, and it was delicious! It's surprisingly useful if you have some, so I recommend keeping it instead of throwing away.
Since plenty of oil comes out from the chicken skin, you don't need to use vegetable oil. If you don't like a lot of oil, please wipe it off with a paper towel. Once you add vegetables, please stir-fry briefly.