The fermented radish known as sinki is a popular ingredient in many Nepalese dishes, along with another fermented vegetable preparation known as gundruk. To make this generations-old indigenous dish, aged radish slivers are pressed into a hole lined with bamboo and straw, then coffined by a cover of vegetation, rocks, wood and, finally, mud. After a month of bacterial curing, the resulting preserved vegetable is dried in the sun and stored to last a few years or more.
The process of making sinki starts by allowing the radishes to wilt for a few days at room temperature. Then, the leafy tops are cut off and the radish tap-root sections are shredded. Meanwhile, a 2- or 3-foot (0.6- or 0.91-m) hole is dug, and a small fire is built at the bottom just before the storage period begins to warm it up.
After the hole is hot, the fire is extinguished and the bottom is lined with bamboo and straw. On top of this goes the radishes, which then are pressed firmly with more vegetation, boards, rocks and mud to create a fairly impregnable barrier. According to the Bioinformatics Centre at India’s North-Eastern Hill University, a month is needed before the sinki is properly fermented by a series of lactic acids. Then, a final sun drying is needed before they can be eaten.
A common dish that utilizes sinki is a simple soup made by first soaking the fermented radishes in water for about 10 minutes, while chopped vegetables like onion, tomato and chili peppers are sauteed in oil. The strained radish slivers then are fried up with the other vegetables, with just a little salt and turmeric powder. This soup, which is commonly served with white rice, is made by adding water and cooking the vegetables for another 10 minutes until all the ingredients are fully tender.
Sinki is commonly fermented and cooked along with another time-honored Nepalese dish called gundruk. This latter food uses the leaves of vegetables like cauliflower and the ones taken from the sinki radishes, storing the wilted and shredded leaves tightly in a covered pot that is kept warm in the sun and over a fire at night. Occasionally, hot water could be added. After about a week, the gundruk can be removed from the pot and dried in the sun. These methods ensure the food will keep until it is time to eat.