Heat a cast-iron or any pan and add all ingredients listed under the “to roast” category one after another as listed.
Add ½ of the oil and lightly roast the walnuts first, and then add lentils and lastly, the cumin seeds.
Once the nuts, lentils, and seeds are lightly brown, just switch off the heat and transfer the ingredients to a blender jar. Allow them to cool.
To the blender jar, add yogurt, chilies, salt, ginger and ½ cup water. I like a runny chutney, so ½ cup water in this chutney works for me. You can reduce the water quantity or skip it if you don’t want a runny chutney.
Blend the ingredients really well and transfer to a large bowl.
Heat the remaining oil in a pan, and add mustard seeds, followed by dried red chilies and curry leaves. Allow the seeds to splutter and chilies to darken. Add the cayenne pepper powder and switch off the heat.
Now, pour the mixture over your chutney.
Serve the chutney with idli, Dosa, fritters or any dish of your choice.