Add all the ingredients except water given under "to grind" in a mixer jar.
Without adding any water, grind the ingredients coarsely and add ½ cup of water.
Grind it smoothly like below. You can add ½ to ¾ cup of water for this measure, and do not add more than that. Transfer it to a bowl.
In a separate tempering pan, heat the oil. When the oil is hot, add the mustard seeds and asafoetida. Let the mustard seeds splutter, and then add the curry leaves. Turn off the heat and let the curry leaves crisp up in the residual heat. Add this tempering to the chutney and mix well. Serve it with idli or dosa. I served this chutney with my celery dosa.
Adjust the salt and red chilies to taste.
As mentioned in the post, you can skip the ginger or add one small garlic clove or a small betel nut-sized tamarind. And instead of dried red chilies, you can also use green chilies.