Also in the awesome KSR area, we had lunch at Aesah Rotdee, a Thai-Muslim place that presents a narrow passage on the street that opens to a wider courtyard.

Table service with almost English that suffers broken Thai. Khao mok gai and (non-alcoholic) drinks all around. Cheap. Clean.

Don't expect to run into a lot of Westerners or Chinese mainlanders. Good alternative to the tourist traps starting a block south.