The humble olive has been consumed by humans for thousands of years – and across the Mediterranean and further afield, the growing, picking, pressing and eating of this versatile fruit is still a matter of wonder and delight

‘There are three pillars of Mediterranean cuisine – olives, wheat and grapes.’ So says chef and food writer Letitia Clark, who lives on the Italian island of Sardinia. She dreams of one day growing and producing all three herself, but for now, she’s content with helping her landlady harvest olives in exchange for a few bottles of oil.

Olive oil is a staple ingredient in Mediterranean cooking and was once so plentiful in southern Italy that it was used to fuel street lamps. The olive tree has been harvested for its oil for millennia, and the product is integral to Greek, Italian, Turkish and Spanish recipes: more than 3 million tonnes are produced worldwide each year, about 69 per cent of it in Europe. But the quality of olive oil varies hugely and can make or break a dish: a good one should smell fresh and peppery, a little like green grass.