Every recipe I try contains garlic, chilli, fish sauce, lime juice and dried shrimp – which fits with Thompson’s direction that som tam “should taste sweet, sour, hot and salty”. The chillies, which should be the incendiary little bird’s eyes rather than the big red milder sort suggested by McEvedy, must be sharp enough to pack a punch; the Bikers’ one between four is not sufficient, while Gabriel’s three between two makes my heart do funny things. Only you know how many you’ll need to make your eyes water while your tongue begs for more, but Thompson also decrees they should be added late in the day, and barely crushed, rather than pounded into fiery smithereens as in some of the other recipes; observing the rule that “the more they are pounded, the hotter the dish – and how hot you want it is up to you”.