First of all, buy the green vegetables wash clean, especially the root part of the vegetables inside the soil should be washed off. Then soak a small handful of dried shiitake mushrooms in warm water. And then cleaned the green vegetables to control the water, the pot of boiling water, after the water boiled to add some salt, and then pour a little cooking oil. Then add the green vegetables, hot about two minutes.
When the vegetables are hot, use a slotted spoon to pull them out and put them in cold water. This step is crucial because the cold water can cool down the bok choy quickly to avoid browning. Then squeeze the bok choy dry and place them on a sheet pan. Now chop them with a knife, just chop the chopped grains to a size suitable for the buns.
Then put the chopped bok choy in a pot and now flavor the pot. Add a gram of edible alkali, edible alkali can make the green vegetables more bright green, and then add a little sesame oil and stir, here first add sesame oil, is conducive to lock the water inside the green vegetables.
This way the bok choy will not turn yellow and will retain its original color
.