Take ½ cup of raw peanuts with their skin and soak them in water for about 2 to 3 hours. Then take a mixer grinder and put the peanuts in it without the water.
Then add ½ cup of fresh coriander leaves without their stem, 4 pieces of fresh green chilies (broken in half), 4 deskinned garlic cloves, and ½ tsp of cumin seeds in the grinder. (Pro tip: Adding garlic is entirely optional. You can skip garlic if you do not want to add it. You can increase or decrease the number of green chilies according to your preference).
Now, add 1 tbsp of sugar to the ingredients in the grinder. (Pro tip: You may skip adding sugar if you want. However, it is better to have a sweet and savory taste in the dahi chutney and so I prefer adding sugar. You can add more sugar if you want).
Finally, add 1 tsp of salt.
Now, grind it once without adding any water to it to get a coarse paste.
Now, add 1 cup of dahi to it. (Pro tip: You can use homemade dahi or store-bought varieties to make this chutney).
Grind everything nicely this time to get a smooth and runny mixture.
Now, add the remaining ½ cup of dahi to the mixture. (Pro tip: Adding dahi in gradually instead of all at once will help it blend perfectly with the other ingredients).
Blend it once again, and when done, transfer it to a bowl.
Now, to prepare the tempering ingredients, take a tadka pan and heat it on a low flame on your gas stove. Now put 2 tsp of ghee in it and when it heats up put 1 tsp of mustard seeds in it. (Pro tip: I have used homemade ghee since I prefer that. You can use store-bought varieties or even white oil if you do not like ghee).
Wait for a few seconds to let the mustard seeds start crackling. When they do, add 4 pieces of dry red chilies to it. Break each of the chilies into small pieces.
When the chilies and mustard seeds stop crackling after a few seconds, add 10 to 15 pieces of fresh curry leaves to it. Let them cook till they lose their moisture and are fried nicely. (Pro tip: Be careful about sprinkling hot oil due to the crackling ingredients during the entire process).
Now, when done, pour the tempering ingredients into the mixture in the bowl. Mix it gently and your sweet and savory homemade dahi chutney is ready to be served with a variety of dishes and snack items.