Not only known for its peculiar name and unique appearance, Nam Dinh's famous "Bun Dua" noodles also impress diners with its light, sweet broth, infused with the aroma of crab roe, all for just 15,000 VND per bowl.

The noodles in this dish are notably thicker than the usual rice vermicelli, with each strand nearly as thick as a chopstick. They are pure white, soft, and chewier than standard noodles.

Ms. Phuong, who owns a small eatery in Nam Dinh City, shared that while Bun Dua may resemble the southern dish "Banh Canh," its strands are thicker, sturdier, and don't turn mushy when served with hot broth.

The noodles are usually paired with a rich crab broth, topped with crab roe and seasonal vegetables like water spinach or water celery, and served with fresh herbs. Some eateries even offer extras like crispy pork fat and pork sausage.

Although the ingredients are simple, each vendor has their own secret to creating a unique flavor.

For the most authentic taste, Ms. Phuong sources her Bun Dua noodles from Cua Nam Ward in Nam Dinh, known for its high-quality noodles. The noodles are naturally white, chewy, and stay fresh longer.

As for the broth, she uses field crabs to ensure a fragrant and sweet taste.

After selecting live, healthy crabs, she cleans them thoroughly and separates the shells from the meat. The crab meat is pounded into a fine paste, mixed with water, and carefully strained to produce a smooth, shell-free crab stock. The more meticulously the stock is filtered, the fluffier and tastier the crab roe becomes when cooked.

The crab stock is simmered over medium heat to avoid boiling over. When the crab roe floats to the surface, it is skimmed off and set aside. Tomatoes and seasonings are added to the stock for a balanced flavor.

The roe from the crab shells is carefully scooped out, then fried with shallots until fragrant. Once golden and crispy, it is added to the stock to enhance the dish with a rich, vibrant color and an appetizing aroma.

"Depending on the season, Bun Dua is served with vegetables like water spinach, water celery, or water morning glory. I often buy my vegetables from Tuc Mac Village, where they’re known for being crisp, green, and flavorful. The vegetables are blanched and drained to keep them fresh and crunchy," Ms. Phuong explained.

When diners order, the noodles are briefly boiled before being served with crab roe, vegetables, and hot broth. Diners can customize their bowl with a splash of vinegar, chili paste, or satay sauce.

"Bun Dua is best enjoyed with a dash of tangy vinegar and some fresh herbs to balance the flavors. Each vendor may offer different herbs, but the usual options are Vietnamese balm, rice paddy herb, and perilla leaves."

"This dish can be enjoyed year-round, at any time of day, and is loved by both adults and children. There are times when I return home after a trip and can easily eat two bowls in one sitting," said Nguyen Hang, a local diner in Nam Dinh.

According to Ms. Hang, Bun Dua is an affordable and simple street food, priced at only 15,000 VND per bowl. It’s rarely found in upscale restaurants, as it’s typically sold by vendors at local markets and small street stalls.

If you ever visit Nam Dinh City, be sure to try this dish at popular spots like Dien Hong Market, Rong Market, Ngo Ngang Market, or at local favorites like Ba Bay Bun Dua (opposite Hoang Ngan Market), Ba Son Bun Dua, and Bun Dua Truong Chinh.

Thao Trinh