Bhapa Ilish

Clean and wash the Hilsa fish pieces thoroughly under running water, then pat them dry with a clean cloth or paper towel.

Grind the yellow mustard seeds, black mustard seeds, and half of the green chilies with a small amount of water to form a very smooth, fine paste.

In a mixing bowl, combine the Hilsa fish pieces with the prepared mustard paste, turmeric powder, salt, and half of the mustard oil. Gently mix to ensure all fish pieces are evenly coated with the marinade.