Surprisingly hard to track down the location of this place but hopefully this is correct. Many different spellings and names for this stall including "Xiang Ji Fish Porridge"
"The old couple, one cooking and another controlling the wood fire and manually fanning it, will soon retire. This is vintage Teochew in Thailand- the freshest chunks and slices of pomfret are simmered in a stock redolent with preserved winter pickles and dried and smoked sole fish bones. You have it with steamed rice. The resultant sweet chunks of pomfret in that smoky and umami blast of flavour in the soup, is why they meander down this little alley for."
— Ranked #12 at the World Street Food Top 50 2017