Ninh Binh is renowned for its culinary delights, including the unique dish ca kho gao, which translates to fish stewed with gao fruit. Although it may not be as well-known as other local specialties like goat meat and crispy rice, it is highly cherished by residents and recommended to tourists.
The name of the dish often leads to confusion, as many people mistakenly think it involves a ladle (gao in Vietnamese) for stewing fish in clay pots. In reality, it features gao fruit, a special local ingredient that can be found in Ninh Binh and parts of the Mekong Delta.
The gao tree typically flourishes near streams and rocky mountain slopes in Ninh Binh. Its fruit, which bears resemblance to rambutans, presents a tangy and slightly sour flavor.
Dishes may use either ripe or green gao. The ripe version offers a milder tang, while the green variant delivers a sharper taste and astringency akin to figs.
Nguyen Hong Thu Trang, a local tourism expert, described her experience with ca kho gao.
For optimal taste, locals prefer using fresh ca ro dong (field perch) or snakehead fish, cleaned and either cut into pieces or left whole.
The gao fruit is sliced and soaked before cooking to maintain its color. Pork belly is often added for an extra layer of flavor, while the seasoning usually consists of fish sauce, caramelized sugar, and pepper.
To start cooking, a layer of ginger, lemongrass, and galangal is placed in the pot. This step is essential for infusing aroma into the dish and preventing any burning. The gao fruit sits atop this mixture, allowing its flavors to penetrate the fish as they cook.
Simmering in a clay pot over wood fire for several hours makes the fish tender and enhances the dish’s aroma.
This dish culminates in a stunning golden hue, with the fish firm and bursting with flavor, balanced by the nutty and tangy profile the gao fruit offers, effectively masking any fishy odor.
“It’s best enjoyed with hot rice, especially in winter. The sourness and slight astringency of the gao fruit pair beautifully with the tender fish,” Trang stated.
Besides making stewed fish, gao fruit finds its way into sour soups, serving as a substitute for other souring ingredients like tamarind or sau (dracontomelon).
For a quick snack, ripe gao dipped in chili salt is a favorite among the youth of Ninh Binh.