Anyone who has travelled to Italy in summer will know that a simple tomato salad can taste transcendently good. Our latest World in a dish column considers why that is the case. The importance of local produce is one factor. So too is variety (some tomatoes are earthy in flavour, others can be sweet or tart). And the right garnishes can seal the deal.

Tomatoes are a staple of Persian cooking, too. And in Iran the fruit also provides a crucial economic lifeline. Though the country’s oil exports are still flowing, it is struggling to collect the proceeds because of American sanctions. That is pushing the Islamic Republic to find new ways to pay for foreign goods. Flooding the Gulf with fruit and veg is one of them.