Andrés Dávila ducks into a covered market in Quito's Unesco-protected colonial centre. Aisles are laden with baskets of colourful fruit, sacks of spices and tables piled high with legs of beef.

He buys a selection of herbs from a smiling matriarch who sells greenery ranging from leaves for tempering altitude sickness to the gherkin-shaped San Pedro cactus, used in the Andes to brew a hallucinogenic soup. We're getting supplies for dinner at Casa Gangotena (+593 2 400 8000, casagangotena.com), a restored historic mansion on cobbled Plaza de San Francisco.