All along the street, there are pushcarts piled up with food; with fried chicken, grilled octopus, satays, spring rolls, meatballs, noodle soup, and pad thai, which the vendor will make to order in seconds. She throws diced chicken into a hot wok, adds beansprouts and rice noodles, an egg if you want one, then soy sauce and tamarind, tosses it together and tips it onto a paper plate. You add a handful of chopped peanuts, a few dried shrimps, a sprinkle of sugar, a glug of fish sauce, chilli flakes, chilli sauce and pickled chilli slices.

My guidebook grumbled that the pad thai from carts around Khao San Road is not authentic, and doubtless it is not, but it was at least as good as I would get in my local Thai restaurant, and I was not complaining for the price of a packet of crisps back home.

The first few times I ate out in Thailand, I tried to order a starter, a main and a side; but it either all came at once or in whatever order it happened to be ready. Thai meals are not structured like that. Rice – a side dish to us, a change from potatoes – is the heart of the meal for Thais. Khao means rice, but it also means meal. Everything else, the soups, the salads, the curries, the grilled fish, is a garnish for the rice. The idea is to have a balance of flavours: Salty, Spicy, Sour and Sweet, the cornerstones of Thai cuisine (and perhaps also the members of a Nineties girl band).

The fish was laid out on ice at the door of the restaurant and the eyes were black, the gills bright red. I had fish every night for a week. Always on the bone, grilled or deep-fried whole, served with a dipping sauce of fish sauce, chilli, lime juice and sugar. Salty, Spicy, Sour and Sweet.

There is a lot more to Thai curries than the soupy green and red clichés the whole world knows. Fiery jungle curry, for instance; and the subtler turmeric, lemongrass and coconut flavours of Massaman curry. Yellow curry paste is smeared over seafood before grilling; red curry paste is stir-fried with pork and green beans in pad prik moo.

I like chilli well enough, but it took me a while to build up the tolerance for incendiary dishes like som tam, made with shredded papaya and enough birdseye chillies to win a bet. I asked a Thai girl how many chillies she would use in a papaya salad. “Hmm, four, six,” she said, as if that were not many.

(c) Richard Senior 2014