Mustard oil is an extremely pungent, yellow-colored oil that comes from pressed mustard seeds. In the raw state, the oil has a bitter, sharp flavor, but once it is heated to the smoking point, the pungency mellows and the oil imparts its delicious flavor to food. It is used extensively in making pickles and chutney as it acts as a preservative. Nepalese apply mustard oil to hair to promote healthy growth and use it in massage for relief from aches and pains. Mustard oil is available in Indian and Asian stores, and some well-stocked supermarkets.