Imagine, if you can, South Asian food without chillies. I find it hard to get my head around such a travesty. And yet there were no chillies in the subcontinent until the Portuguese brought them from Central America in the early 16th century. So although desi — and many other Asian cuisines — are defined by the spicy heat imparted by green and red chillies, there was a time when this key ingredient was missing. But once South Indians took to it like ducks to water, chillies gradually became popular from Srinagar in Kashmir to Szechuan in China.

The other day, the lady wife picked up a few Scotch bonnets in Portobello Market. I had never used them before, but had read they were lethal. So when I cooked some qeema-aloo for six people and decided it wasn’t hot enough, I thought I would throw in some of these chillies. Small, round, bright red and with a few pleat-like lines, they did resemble bonnets. I sliced one into tiny pieces and sautéed it with a little garlic before mixing it into the mince-meat. The result was electrifying. And even though I washed my hands with soap twice after handing the chillies, I still managed to sting my eyes after accidentally touching them.

In our garden in Sri Lanka, Nandi, our wonderful cook, has planted some tiny, bright green chillies that I have dubbed tataya. These are very hot, but nothing like the Scotch bonnets. A hundred years ago, Wilbur Scoville, an American chemist, devised a test to measure the spicy heat of capsicum concentration in chillies. Known as Scoville Heat Units (SHU), these range from the low thousands to the millions. At our local food festival, I found a farmer selling chillies and bought something called ‘moruga’ at three for a pound. He warned me to be careful and just as well: while researching this article, I discovered they were also known as Trinidad Scorpions and rated at two million SHU. I will now treat them with the respect they deserve.

Another killer chilli is the famous naga (viper) or bhut (ghost) jolokia from Nagaland in India. Also grown in Dorset in the UK, the chilli is sold in some supermarkets where you have to prove you are at least 18 before being allowed to buy it. By contrast, the Mexican jalapeno measures only around 5,000 SHUs. The large dried Kashmiri red chillies would barely register on the Scoville scale, but nevertheless impart depth of flavour to a dish.

So you think you know your spice? Think again

Before the fortuitous advent of the chilli, Indians used black peppercorns as the basic spice. These were in great demand in Europe to liven up the bland food and Greeks and Romans imported pepper in large quantities. When Christopher Columbus set off on his epic journey in 1492, he was trying to discover a passage to the fabled Spice Isles. And when he tasted spicy food in the Caribbean, he was convinced that the natives were using pepper, and he had therefore succeeded in finding the Indies. Hence, the name ‘Indians’ given to the indigenous people of the Americas.

In her extremely well-researched book Curry: A Tale of Cooks and Conquerors, Lizzie Collingham writes: “Of all the foods they introduced to India, chillies are undoubtedly the most important Portuguese legacy. And yet, even at the end of the 17th century, chillies were largely confined to the south of India. Two centuries after the Portuguese first landed at Calicut, the chilli had still not reached the northern plans of Hindustan. It arrived with the Marathas, a wild and unruly group of people from the Deccan in central India who contributed to the decline of both the Mughals and the Portuguese.

“An English visitor to the area in the 17th century described them as ‘naked Starved Rascals, accustomed to Fare Hard, Journey Fast, and take little Pleasure’… A north Indian scholar and poet argues that the Marathas’ nature was ‘dry and hot’ because they ‘put chillies in everything they eat’. This custom, he claimed, accounted for their warlike and determined character. In contrast, it was said, the Mughals, accustomed to diet of rice pilaus, almond sweetmeats and central Asian fruit, had become soft and ineffectual…”

Vindaloo is a classic Goan dish created by a fusion of Portuguese and South Indian influences. This has tamarind, jaggery sugar, mustard seeds, lots of dried and fresh chillies and the usual spices that are simmered gently with meat that has been marinated overnight.

The demand for spices drove exploration and ultimately led to colonialism when traders discovered how weak local rulers were.

Published in Dawn, Sunday Magazine, June 1st, 2014