Heat oil in a pan and add cumin seeds, mustard seeds, and dried red chillies. Fry for a few seconds until fragrant.

Add chopped onion and garlic and sauté until the onion turns translucent.

Add chopped red bell pepper and sauté for a few minutes until it softens.

Turn off the heat and let the mixture cool down.

Once cool, transfer the mixture to a blender and blend until smooth.

Add salt to taste and blend again.

Serve the chutney with dosa or idli.