Martha Ortiz glides through Mexico City’s San Juan market like a ballerina, reed thin and elegant. She pauses at a produce stall, a kaleidoscopic tower of fruit and vegetables, and extends a lissom hand to accept a slice of a red-fleshed pitahaya. Onwards to a chilli stall, fragrant with smoky spices, where she wafts a pasilla mixe variety under her nose, as gracefully as if it were a rose. For the full article click here.