Though it is easy to grow, the black mustard seed (unlike its
brown and white counterparts) must be harvested by hand.

Used in food:
They are the most pungent of all mustard seeds, and are an integral part of Indian and Pakistani cooking. Warming the seeds helps temper mustard’s inherent spiciness and allow the full range of flavours—from the nutty to the floral—to bloom. When soaked in water the myrosinase is activated and the dish will benefit from an intense heat and pungency. A trick is to heat or toast the seeds in hot oil or ghee instead. Add towards the end of cooking if it’s been ground into powder.
 
Natural benefits may include:
Strengthen bone, teeth, hair & nails
Antioxidant
Source of vitamin A, vitamin C, calcium, magnesium and iron
Help relieve water retention (edema)
Increase appetite
Anti - Aging