Bring a pot of water to a boil and add a little salt.

First add the stem part of the choy sum to the boiling water, wait 30 seconds, then add the leafy parts. Blanch the greens for about 2 minutes or until tender.

Drain the choy sum in a colander. Lay them on a cutting board and slice them in half lengthwise. Transfer the greens to a serving dish.

Heat the oil in a small pan over medium heat. Sauté the garlic until fragrant. Add the soy sauce, water, and sesame oil; mix well.

Remove the pan from the heat and pour the sauce over the choy sum. Serve hot.