With a hot flavour, the microgreens can be used to add pungency to salads, while the large mature leaves can be cooked as a potherb.
Immature flowering stems can be eaten as a broccoli substitute.
Black mustard seed is a commercial ingredient in food relish and curries and can be used whole in pickles, curries and sauerkraut. Stronger and more pungent than white and brown mustard.
Mustard seed is often used as a rubefacient poultice, or added to hot water makes a stimulant foot bath, good for colds and headaches. Internally the seed is used as an appetizer and digestive. The seed is eaten as a tonic.
Mustard can be grown as a green manure.