The four fundamentals of Southern cooking are, saltiness, sourness, seafood and, most importantly, spiciness. Janhom has all four foundations solidly laid down, making it top for authentic Southern cuisine in the capital. Here, there is no sugar to accommodate Bangkokians and only solid tongues can take the heat. Janhom’s matriarch hails from Surat Thani and her reputation reaches all the way to Chiangmai, where she has another branch. Despite its uncompromisingly hot dishes, an increasing number of patrons are coming from far and wide to this non-descript soi in Ramkamhaeng, making this a restaurant that’s full of activity, especially at dinner. The seafood is fresh, using creatures such as saltwater crab and fishes, particularly seabass and mullet fish (plaa krabok). The must try here is the kaeng som; have it with bamboo shoots (naw mai) and seabass. The soup is not Songkhla-spicy but close enough and is flavorful thanks to the pervasive aroma of the bamboo. Another Southern staple is sataw (the pungent green bean pod); have it stir-fried with kapi (shrimp paste) and shrimp. This restaurant version uses garnishes such as big chilis and onions. It’s not as sour as the one your Had Yai grandma would fry up (with more kapi, turning it into a big grey mess) but the big, fresh sataw are succulent. A rare soup in Bangkok is the South’s tom som, which is normally boiled with luuk daal (palmyra palm), giving the soup its tangy flavor. We have an inkling this place cheats by using vinegar, but nonetheless the soup attains the perfect requisite sourness. Every Southern meal has to be accompanied by chili paste served with assorted veggies. The veggies here are sad-looking but the phrik kung sot saves the day; it’s so clean you can still taste the shrimp underneath the strength of the kapi. Despite average service, the plain one-story shophouse is one of the best Southern kitchens in town and is worth the trek for those willing to cry (out of painful joy) for and during their supper. No corkage charge.