Khao soy is a staple in this town and few places do it better than Lampang Lert Rot (ลำปางเลิศรส). Much has been made of Chiang Mai's signature dish (though if you want real Northern Thai food you have to look elsewhere), with fancy restaurants opening up on Nimmanhaemin and there are even rumors of one run by a farang. But long before the influx of nouveau riche Bangkokians and the western fascination with Thai food the people of Chiang Mai ate dirt cheap khao soy from unpretentious street stalls, and this is where its glowing reputation comes from. If you want the real deal, head on over to Lert Rot.
They do other dishes, including red pork belly and deep fried dumplings, but khao soy is really their main draw. A bowl should run you about 30-40 baht.