Bitter vegetables in Vietnamese cuisine
There are several types of “bitter vegetable” (Vietnamese: rau đắng) used mostly in southern Vietnamese cuisine. Previously, those bitter vegetables are grown for their medicinal uses in Vietnamese traditional medicine. Some of them are also found in Vietnamese dishes.
Of all the bitter vegetables, the most common leafy bitter vegetable is Glinus oppositifolius (Vietnamese: rau đắng đất or rau đắng lá vòng or simply rau đắng), which is a species of the family Molluginaceae. This is also considered the most delicious one of the bitter vegetable group. This is used for cooking soup (with fish, shrimp, crab, minced meat …) or eaten raw together with other vegetables (like in some fry dishes, or bánh xèo pancake dish) or can be used fish porridge… The most prominent dish with this bitter vegetable is cháo cá lóc rau đắng (snakehead fish porridge with bitter vegetable).
The next common bitter vegetable is water hyssop (Bacopa monnieri, Vietnamese: rau đắng biển or biển súc), which is a perennial, creeping herb of the family Plantaginaceae. It commonly grows in marshy areas throughout Asia and it is also found in Florida, Texas, and Hawaii. Some other names include waterhyssop, brahmi, thyme-leafed gratiola, herb of grace, and Indian pennywort. In Vietnam, it grows profoundly in Mekong Delta. The locals use water hissop as raw vegetable with or with other vegetable in some fry or grill dishes. Water hyssop can also be poached (or boiled) to reduce the bitterness, as in a dish which consists of poached water hissop dipped in braise pork sauce, braised fish sauce, soy sauce, fermented fish or shrimp paste, or “kho quẹt” paste. Water hissop can also be stir-fried with pork and prawns in coconut milk, which becomes a delicious dish. Or the bitter vegetable can be used as a nutritious soup vegetable paired with aquatic food like fish, prawns, crabs,…
Another bitter vegetable is Enydra fluctuans (Vietnamese: ngổ trâu). Their leaves are stir-fried with beef, or shrimps or are used in braise dishes.
Limnophila aromatica (Vietnamese: ngò ôm or ngổ hương or rau om), the rice paddy herb, is also used as vegetable. Limnophila aromatica is often confused with Enydra fluctuans. The former is used as herbs in some soup dishes like taro soup, snakehead fish porridge, or canh chua, a Vietnamese sour soup, and also in pho.
Much lesser known bitter vegetable is Clerodendrum cyrtophyllum (Vietnamese: rau đắng cảy, or bọ mẩy) in Phu Tho, a northern province in Vietnam. The local resident often stir-fry the leaves with eggs, or poach them to get dipped in salt and sesame mixture, or steam them in bamboo tubes, or sometimes cook them in soups.
Asiatic pennywort (Centella asiatica, Vietnamese: rau má) is probably the least bitter vegetable of all leafy bitter vegetables. In Vietnamese suisine, Asiatic pennywort leaves can be blended into smoothies, or cooked with minced meat in soups, and also used a hotpot vegetable.
The most common non-leafy bitter vegetable is bitter gourd or bitter melon (Vietnamese: khổ qua or mướp đắng). In fact, it is the most popular bitter vegetable in Vietnam. Bitter gourds can be sliced and stir-fried with duck eggs, stuffed with minced meat in a a bitter soup of the same name.