Dry roast peanuts and cool it completely.
Take a pan, add few drops of oil, chillies and coarsely chopped tomato(optional), tamarind(you can skip if tomato is tangy).
When the tomatoes got mushy, add tamarind and salt and keep it aside. In a blender, add roasted peanuts and ground it coarsely then add tomato and green chillies and sufficient water to make a fine paste.
Meanwhile heat oil in a pan, add musturd seeds when splutters add cumin seeds, channa dal and urad dal turns golden, add red chillies and curry leaves. Switch off the flame and pour this over the peanut chutney.
Serve chutney with either Idly or Dosa or pesarattu or oats pongal