Cooks from Bengali-speaking homes are masters at creating magic with fish. Jhols are saucy dishes, usually incorporating pungency, sweetness, and tartness in one harmonious curry.
Combine the turmeric and the lime juice in a small bowl, and stir to dissolve the turmeric. Place the catfish fillets in a baking dish, and pour this thin, tart, yellow juice over the fish. Lift the fillets to allow the liquid to pool underneath. Refrigerate, covered, for 30 minutes to 2 hours. (Do not leave it overnight—the acidic lime juice will break down the flesh, crea