Mustard Seeds - Rayo or Sarysun - (तोरी, राई)

Mustard Seeds - Rayo or Sarysun - (तोरी, राई)
These small round seeds come from mustard plant, a common annual field crop.  They range from reddish-brown to dark brown color, but when crushed they are yellow on the inside.  They have a pungent, sharp flavor, but when fried in oil, they impart a mellow nutty flavor.  

Preparing Nepalese pickles (achaar), the ground and coarsely ground mustard seeds are used, they are must have ingredients because of their wonderful preservative properties, which discourages mold and bacteria.

Mustard Seeds bought at the Indian grocery store.

In the above picture (L to R) crushed yellow mustard seeds, Dijon mustard, finely ground mustard, brown mustard seeds, Crushed brown mustard, dark-brown mustard seeds, and the center is pale-yellow mustard seeds

Mustard seeds range from reddish-brown to dark brown in color.  Photo taken at Nepali spice markets.

Yellow mustard seeds (sarsyan) are used to cook fish and are believed to eliminate fishy odors.