The fingerroot (Boesenbergia rotunda) belongs to the the ginger family (Zingiberaceae) and it usually grows in damp shaded lowland areas or on hill slopes, as scattered plants or thickets. It is native from southern Yunnan Province, China, to the western parts of Southeast Asia. The common English name refers to its finger-like rhizomes.
In Vietnam, this species is, however, less popular than other ginger family species such as ginger or galangal. In fact, it was introduced to Vietnamese cuisine only after the Cambodian Vietnamese came back to Vietnam. Vietnamese people in the Mekong Delta provinces who came to Cambodia to settle their lives have brought the fingerroots back to Vietnam and grew as a culinary spices.
Fingerroots are used in various noodle dishes such as bún nước lèo (a fermented fish noodle soup) and bún kèn dừa (a fish noodle soup with coconut milk), two indispensable dishes in the Vietnamese families who once lived in Cambodia, now living scatteredly in Vietnam’s southern provinces. That’s why the species is known as ngải bún in Vietnamese language, which literally means “noodle arrowroot”.
Fingerroot is propagated from rhizome cuttings at the beginning of the rainy season in the southern Vietnam, around the beginning of May. Soil must be well-drained, not waterlogged, usually black soil mixed with small pebbles. Fingerroot leaves are simple, long, lance-shaped, similar to turmeric leaves but smaller. Fingerroot flowers are usually not visible. After about 5, 6 months, at the end of the rainy season, leaves become dried, and people dig up the roots. Fingerroots are clustered like chicken feet, growing in long bulbs. The largest tuber is only the size of a little finger. The color ranges from white to pale yellow. When the fingeroot is broken in half, the inside has a milky white flesh with a darker yellow core.
Fingerroot has a gentle aroma, a strong taste, reminiscent of the taste of the land, wild mountains and forests. To cook noodle soup with fingerroot, one must use fresh ones. Dried fingerroots will lose much of its flavor. Vietnamese home cooks only cook with freshly-harvested roots. The roots are washed, peeled and then pounded. Then the root paste are added with a little water to boil in a pot. The root sauce or juice is filtered to remove the residue.
Lean fish are preferred, such a bagrid fish (a type of catfish), red fish are the second choice. One kilogram of fish can cook for four people. Bring a pot of water and fish to a boil, remove the fish bones to separate the lean meat, and then crush the bones. Turmeric, garlic, roasted peanuts are also crushed and mixed with fish and fingerroot juice. Add a little sugar, monosodium glutamate, crushed chili and a little bit of fermented fish (known as prahok in Khmer language) then mix well. Grate half an old coconut to get coconut milk, and set aside. Filter the boiled fish broth, remove the foam, add coconut milk, and bring to a boil. When the fish broth has boiled, add the seasoned fish, and continue to cook until it boils again. Add two cloves of lemongrass. As soon as the meal time is up, pour in the coconut milk as the last step. Thus, we have finished cooking the rich broth with the characteristic flavor of fingerroot.
Vegetables eaten with fingerroot fish soup are also a special anthology of: finely chopped cowpeas – raw bean sprouts – chopped banana blossoms – river tamarind buds (Leucaena leucocephala) and minced cucumber. The noodle soup dish must be served hot to retain the deliciousness. If it is not spicy enough, one can add chili salt as a condiment.
Whoever eats this noodle soup once will remember the taste of fingerroot for life. It reminds us of the wild atmosphere of unexplored forests. It reminds us of the fiery vitality of the muscles crossing mountains and passes to reclaim the wastelands… In Ho Chi Minh City, if you want to this fish-fingerroot noodle soup, or those who miss their hometown must go to Tan Huong – Tan Phu area, Tan Binh district, where many Cambodian Vietnamese live.
