Mustard seeds, or Sarso Dana, are small, round seeds that come in yellow, brown, or black varieties. They have a sharp, pungent flavor and are widely used in cooking to add a spicy kick to dishes. Mustard seeds are commonly used in tempering, pickling, and making mustard condiments. When heated, they release a nutty aroma and flavor, enhancing the taste of curries, stir-fries, and marinades.