Mustard oil is an extremely popular oil among home cooks in China, Russia, and in South Asia, particularly in the northern Indian state of West Bengal as well as in Bangladesh and Pakistan. Unlike oils that are merely infused with mustard seeds, true mustard oil is the fat extracted from the seeds of the mustard plant—in India, the oil is extracted from black mustard seeds from Brassica nigra. While in Russia and China, it’s extracted from the brown mustard seeds from Brassica juncea.
Just like most cooking oils, mustard oil has a diverse set of applications. You can use it to sauté or stir-fry vegetables, and its aromatic qualities make it perfect for heating spices and chilies for tadka—the hot, seasoned oil that’s used as a finishing touch for many dishes. Also, because it has a particularly high smoke point—about 480°F [248.89°C], which is higher than canola or even grapeseed oil—it’s a great fat to deep-fry stuff in, like battered chunks of fresh fish, and it can be used in place of olive oil when roasting vegetables.