This drink or you call it a dessert is called “sâm dừa” in Vietnamese where “sâm” means ginseng, and “dừa” means coconut. Of course there is no such thing like coconut ginseng. In fact, this drink consists of coconut juice and young coconut flesh mixed with “gingseng water” (nước sâm) cooked by various medicinal herbs in Vietnam. In this sense, “ginseng” here, in a broader meaning, is equivalent to tonic medicinal herbs. This drink is originated from Can Tho, a city in southern Vietnam.
It is very easy to make this tonic drink, but you need to collect many ingredients. There are several different recipes to cook nước sâm (gingseng water) with different ingredients. But in this drink, you will need: sugarcane, water chestnut, corn silk, cogon grass roots, pandan leaves, brown sugar and a specific herb named Pouzolzia zeylanica (cây thuốc dòi). Optionally, you may want to add boat lily, coriander, monkfruit, and the cooked roots of Rehmannia glutinosa (thục địa). This is the recipe that requires the most ingredients, but also the one that may quench the thirst most in Vietnam. You will simply cook all these herbs in a pot of water for about 30-40 mins then add some brown sugar. The outcome is a brownish herbal juice.
Sliced coconut flesh (from young coconuts) is the common topping, but sometimes it can be replaced with coconut jelly. Dried longan can also be added. The drink is served with some shaved ice.
Rinse and cook all the herbs including the roots and the monkfruit in a pot of 5 liter water on low heat. Cook for about 45 mins, then drain for the herbal juice. In a different pot, add back the juice together with brown sugar and then bring the juice to a boil. Stir to make sure the sugar is fully dissolved.
Dried longan, dried chrysanthemum flowers, and dried seaweeds can be used as a substitute, but the final taste may vary.
Theoretically, you can cook with real ginseng.