Black cardamom is the dried seed pod of Amomum subulatum, a tall perennial herb of the ginger family native to the eastern Himalayas. Far larger and darker than the green cardamom it is often confused with, its rough brown pods are dried over open fires, which leaves them with an unmistakable smoky, resinous, camphor-cool aroma. It is a savoury spice — a workhorse of North Indian, Nepali, Tibetan and Chinese cooking that anchors garam masala, slow braises, biryanis and pho rather than the sweets and desserts where green cardamom belongs.