Nai Lek Uan is one of Yaowarat's most long-standing and beloved street stalls. Bangkokians queue for a taste of their kuay jab, rolled rice noodles and crispy belly pork in a peppery soup.

Like much of Thailand's fare, the noodle soup's roots are in China, specially the Teochew people who brought the recipe where it was adapted to Thai taste. It perfectly illustrates the country's strong assimilation with Chinese culture. Similar bowls of kuay chap are found across South East Asia.

They set up nightly along the main neon-lit drag of Yaowarat Road in the heart of Bangkok's Chinatown. It's a chaotic space surrounded with a hive of passing pedestrians, honking tuk tuks and a cluster of frantic pushcarts. It's popularity means there's almost always a line of hungry punters, but service is quick and it's worth the wait for one of the few tables.

The simple pushcart has changed little over the decades, but in recent years they've erected a modern neon-lit sign helping it stand out a little from it's neighbouring competitors. There's little need to though, just look for the snaking queue. Bowls of the clear pork-bone broth with just the right balance of flavours - garlic, white pepper, coriander root and herbs dotted with pork belly crispy enough to hold its crunch in the soup is a revelation and leaves little doubt why they are slammed daily from 6pm through to close at midnight.

Seasoning table condiments like white pepper, chilli flakes and chilli vinegar can be experimented with if you like a little more kick, but aren't strictly needed. Bowls are 50 THB (around US $1.60). Another 80 THB ($2.60) will get you an extra plate of belly pork, always a good idea.

Finding Nai Lek Uan requires walking up through Yaowarat Road at its busiest time. Try to get there as early as you can or indeed late into the evening because things heat up around dinner time.