Fill a medium sauce pot with water and bring it to boil.

To prepare the yu choy, trim a small amount of bottom end away to remove the dry tip ends, about a little less than a quarter inch.

Plunge them into a bowl of cold water a few times to rinse. Also gently separate each layer to rinse away hidden dirt. Set aside to drain.

Finely mince the garlic and combine the sauce ingredients from oyster sauce to garlic chili sauce, if using, in a small bowl. Stir well.

Once the water has come to a boil, lower heat to medium-high. Gather the yu choy into a large bundle with the stems facing downward.

Place the bundle into the water, stem side down in standing position with the leafy parts above the water, and blanch for 45 seconds. If the stems are thicker (more than 0.5-inch), blanch for a little over 1 minute.

After that, submerge the entire bundle with the leafy parts to blanch for 30 more seconds.

Remove the yu choy and rinse or shock them in cold water to stop cooking. Gently squeeze out the water and transfer to a large serving plate.

In a medium pan, preheat over medium heat until it feels warm. Add the oil, swirl it around, then add the garlic. Quickly saute over medium heat for 10 seconds. Take care not to burn.

Pour in the sauce, gently stir the pan with a wooden spoon for 30 seconds to infuse the sauce with garlic flavor. We don’t want to cook the sauce down. Just to warm it up. Turn off the heat.

Pour the sauce over the yu choy. Serve immediately, warm, or at room temperature.