Maacher kalia or maacher jhol is a simple bengali fish curry that is a favorite in many indian families. Maacher means "Fish" And kalia or jhol means "In curry or gravy. " The most commonly used fish to prepare this dish is a type of freshwater carp or rui maach. If you do not have access to rui maach, you also can use salmon, pomfret, sea bass, red snapper, tilapia, or catfish. Unlike in other parts of india, bengali recipes call for the frying of the main ingredient in mustard oil before it is added to the gravy or curry. This is thought to enhance flavors and cause the fish/meat/eggs to absorb the spices in the gravy better. In some bengali homes, this frying translates to deep-frying, while in others it means pan-frying. Take your pick depending on your preference.