Fiery Chile Mustard Relish (Bengali Kasundi)

Kasundi is one of Bengal’s great condiments, and this version wastes no time getting to the point. Five ounces of fresh red hot chilies, a tablespoon of mustard seeds, four cloves of raw garlic, and a small green mango all get blended into a smooth, searing paste. That’s it. No cooking. Just raw heat and bright, sour punch.

The green mango is what makes kasundi different from a standard chili paste. Unripe mango brings a sharp tartness that balances the heat and gives the relish a fruity complexity you won’t find in vinegar-based hot sauces. If you can’t find green mango, look for it at Indian grocery stores, usually labeled “raw mango” or “kaccha aam."

Mustard seeds add a pungent, almost horseradish-like bite that hits the back of the nose. Combined with the garlic and chilies, it creates layers of heat: the slow burn from the peppers, the nasal kick from the mustard, and the sharp sting of raw garlic.

A little goes a long way. Start with half a teaspoon alongside grilled chicken or spooned into a sandwich. This is meant to be a condiment, not a side dish. It keeps in the fridge for up to two weeks, and the flavors mellow slightly as it sits.

Chef Tips

• Wear gloves when handling the chilies. Five ounces of fresh hot peppers will coat your hands in capsaicin that soap alone won’t remove.
• Blend until very smooth. Any chunky bits of mustard seed will be gritty and unpleasant.
• Adjust heat by removing some or all of the chili seeds before blending.

Variations

• Milder version: Replace half the hot chilies with mild red bell pepper for color without the full blast of heat.
• Vinegar kasundi: Add 2 tablespoons of white vinegar for a sharper, more shelf-stable relish.