The Mexican city of Monterrey, 1968… a 21-year-old Englishman named Rick Stein orders a taco that is to change his life.
Rick Stein says this was his first experience of truly exotic cuisine – "It had chilli, it had lime, it had avocado and coriander in it. It was so fresh-tasting."
The British chef celebrates the flavours of Mexico in his latest cookbook The Road to Mexico.
In the accompanying BBC television series, he eats and drinks his way from San Francisco to the southern-most tip of Mexico.
Stein started his tour in California because it used to be a part of Mexico and there's a lot of Mexican influence in the food industry there.
"Virtually everything that's grown in California is grown by Mexicans … This whole idea of Trump keeping the Mexicans out is just ludicrous because there's nobody else to do the work."
Stein told his researchers that when he got to Mexico he wanted to visit the kind of "gnarly taco joints" and the "slightly low-life cantinas" he remembered from the '60s.
"In my 20s I had no fear so I did tend to go into dives because they were cheap."
Why does he think Mexican food has overtaken Chinese food to become the most popular cuisine in the UK?
"The extraordinary combination of savoury, spicy, fresh and sour."
Stein doesn't have anything against nachos or fajitas, but instead of the "rather rich, cheesy, meaty dishes" often served in the UK – a fusion of Mexican and American food called Tex-Mex – the recipes in the book are for lighter and fresher dishes, he says.
The absolute essentials of Mexican food are corn tortillas – homemade taste best – dried chillis such as serrano or habanero and refried beans.
Stein loves refried black beans with everything.
Although in The Road to Mexico he recommends cooking them in oil, nothing beats lard, he says.
"They've got to be cooked in lard – there's nothing else. Even goose fat doesn't taste as good. The lard taste in refried beans means a lot to me."
His favourite dish of the whole trip was an Aztec dish called a Povole that was cooked for him by a 'housewife' in Oaxaca. It's a chicken stew with whole kernels of corn, coloured green by serrano chilli and coriander and thickened with pumpkin seeds.
Street food isn't the domain of poor people in Mexico, everyone eats it, Stein says.
"They're good Catholics and they're good family people so they have a great love of their family dishes."
Mexican people enjoy a laugh and are always hospitable, he says.
"In Mexico, you really feel they are pleased to see you. They've got this tradition of welcoming strangers … I haven't yet found anybody who's gone to Mexico on holiday and not completely loved it."
Check out Rick Stein's recipe for Ensenada fish tacos with chilli and coriander.
You can find further recipes from the book here.
The Road to Mexico will screen in New Zealand next year.