11 Secrets to a Perfect Bengali Fish Curry Recipe

2. Use cold-pressed mustard oil and learn how to tame its heat

Mustard oil (sarson tel) is a signature in Bengali fish curries. It lends a pungent, nutty heat that pairs naturally with mustard pastes and green chilies. If you can get food-grade cold-pressed mustard oil, use it for the authentic aroma. Heat it just until it shimmers, then let it cool slightly before adding spices; heating it past its smoke point can make it bitter. If mustard oil is restricted where you live, use a neutral oil mixed with 1–2 teaspoons of mustard powder to mimic flavor. Start with two tablespoons of mustard oil for a 500g batch and adjust to taste; the oil helps carry flavor and gives that characteristic finish. When you temper whole spices, add them once the oil is hot but not smoking so they bloom without burning. Learning the oil’s behavior—how it sizzles at different temperatures—lets you control bitterness and get the bright, toasty notes that make the curry sing.