Wash and drain choy sum thoroughly. Trim 1 inch off the end of the stalks. Cut off each leave from the stalk and then cut the leave into 2 or 3 bite size pieces, about 2 to 3 inches in length. Cut the top part of the remaining stalk into bite size pieces as well. Stems and leaves should preferably be separated.
Place vegetable oil, sesame oil, and minced garlic in a small microwave proof dish and microwave for 1½ minutes on high. Remove and add soy sauce. Stir to combine.
Bring a large pot of water to boil. Add choy sum stalks for 10 seconds followed by the leaves. Remove with a metal strainer as soon as they turn a bright green color. This should take approximately 2 minutes.
Alternatively, choy sum can also be placed in a large microwave proof bowl. Microwave for 3 minutes on high.
Place choy sum in a large bowl. Press vegetables with strainer to remove excessive water. Pour garlic soy dressing over vegetables. Mix well and serve immediately.