Heat a skillet or sauce pan and add a teaspoon of oil.
Add chana dal or Bengal gram daal, dry coriander seeds, cumin seeds and curry leaves.
Cook until the mixture turns slightly brown.
Add tomatoes, green chili and garlic.
Cover and cook until the veggies are soft and start to lose water.
Add salt and stir well.
Let the mixture cool down completely.
Blend well to make a smooth paste.
Adjust salt and the tang. If required add some tamarind paste and blend again. It is totally optional to add tamarind paste.
Season with toasted mustard seeds and curry leaves.
Or splutter some mustard seeds and curry leaves in oil and add it to the chutney.
Serve at room temperature and refrigerate leftover for not more than three days.