Wash and drain gai lan thoroughly. Trim ½ inch off the end of the stalks. Peel the end of the stalks with a paring knife. Set aside.
Bring a large pot of water to boil. Add prepared baby gai lan. Blanch until they turn a bright green color, about 3 to 4 minutes.
Prepare an ice bath by filling a large bowl with cold water and ice cubes. Remove blanched gai lan from the boiling water into the ice bath to stop the cooking. Drain the water and transfer cooked gai lan onto a plate.
Heat vegetable oil in a small saucepan. Saute garlic and ginger for 1 to 2 minutes over medium low heat until lightly brown. Turn off stove. Add oyster sauce and soy sauce. Stir to combine.
Pour dressing over cooked gai lan. Serve immediately.