Watercress boils in soup with sweet dates and luo han guo helps to expel heat from the body and tonify the lungs. Besides boiling with soup it was delicious when stir fry with garlic and oyster sauce.
Wash the vegetables thoroughly before cooking as there are insects and worms clinging to the leaves. Nowadays the vegetables are sold without roots and makes it easy to prepare. Fry the vegetables with garlic over high heat not more than 5 mins to retain their color and texture. Stir in oyster sauce last.