Khao Soi, which you’ll occasionally see in a restaurant’s name, is the pride of the North. It’s a noodle soup with many different fillings, but always topped with a ‘nest’ of fried noodles. There are a few specialized restaurants that serve nothing but Khao Soi, but you can actually get it everywhere in regular Thai restaurants.
Check these out:
KHAO-SO-I, a trendy new spot, sometimes with a queue at the door.
KHAO SOI MAE SAI, which even earned a Bib Gourmand in the Michelin Guide (and yet the soup costs less than 100 THB)...
Both restaurants are located a bit north of the city, so you’ll need transport to get there.
By the way, it’s a typical LUNCH dish, so the doors close at 5 PM.