The flowers of the bougainvillea plant give sticky rice from Son La its yellow color and honey-like aroma. Photo: Truong Son

The Phlox flower is found in many areas of Son La province such as Sop Cop, Song Ma, Thuan Chau, Muong La, Ngoc Chien...

This flower typically grows in humid, cold, and foggy climates. Locals can harvest it during the season to sell fresh or dry it for later use.

Bougainvillea flowers are intensely colored and have a honey-like fragrance. Photo: Truong Son

Not only is it a wild flower, but the bo phon plant is also used as a coloring agent for many traditional dishes, most notably the bo phon sticky rice of the Thai ethnic group.

In Ngoc Chien commune, sticky rice wrapped in banana leaves is a dish commonly prepared by locals to entertain guests or serve on important occasions.

This sticky rice dish is impressive because of its natural golden color, unlike other types of sticky rice that are colored using familiar leaves, roots, or flowers.

To make delicious sticky rice, glutinous rice is a carefully selected ingredient. According to Ms. Ca Thi Thoa, who has many years of experience preparing traditional dishes in To Hieu ward, fragrant glutinous rice with round, plump grains, especially the "tan" variety, is often used to make "xoi bo phon" (sticky rice wrapped in banana leaves).

"The amount of flowers used must match the amount of rice. On average, about 10kg of rice can use a small bunch of flowers, about 100g. If you use more or less, the color of the sticky rice will change," Ms. Thoa shared.

Dried or freshly picked bougainvillea flowers are washed and boiled in a pot for about 5-10 minutes. When the water turns yellow, the flowers are removed, the water is allowed to cool, and then used to soak glutinous rice.

After washing, the rice is soaked in water infused with the scent of the "bó phón" flower for about 4-5 hours, or overnight depending on the preparation method. Once the rice has absorbed the color, it is drained and then steamed.

The flowers of the bougainvillea plant are boiled for about 5-10 minutes, then the resulting liquid is used to soak the rice. Photo: Truong Son

According to experienced sticky rice makers, to ensure the rice grains cook evenly, become firm, and chewy, the sticky rice can be steamed twice. The first time, when the rice is about 80% cooked, it is poured onto a tray to cool and drain off excess moisture. Then, the sticky rice is steamed again until fully cooked.

When the lid of the steamer is opened, the glutinous rice grains turn a golden yellow like honey, plump, fluffy, and chewy. The aroma of the glutinous rice blends with the distinctive scent of the bougainvillea flower, creating a dish with a unique flavor.

After steaming, the sticky rice is usually poured onto a tray lined with banana leaves, fanned to remove excess moisture, and then placed into a "ép khảu" – a traditional container for sticky rice used by the Thai people. This method helps the rice grains retain their chewiness without becoming mushy.

Ms. Hoang Thi Hue, a tourist from Lao Cai province, said she has visited Ngoc Chien many times and enjoyed the local ethnic dishes.

"Sticky rice with 'bo phon' has a beautiful yellow color, the grains are soft, fragrant, and have a distinctive flavor. Every time I come here, I buy some to take home as gifts for my family," said Ms. Hue.

Sticky rice with toppings is often eaten with sesame salt, peanut salt, smoked meat, grilled fish, or chili sauce. In the five-colored sticky rice platter of the Thai people, the yellow color also symbolizes abundance and prosperity.

Sticky rice with toppings has a golden yellow color, and the grains are even and glossy. Photo: Truong Son

From flowers blooming in the mountains and forests, the Thai people create sticky rice with a natural yellow color and a unique preparation method. Sticky rice with flowers is not only a staple on the dinner table but also contributes to preserving the traditional culinary culture of the Thai people in Son La.

Through these simple dishes, the products of the mountains and forests continue to be preserved and become a distinctive feature of the local culture.