Add vegetable oil to a heavy bottomed pot and allow to heat up. Add garlic, ginger, urad dal, chana dal, dry red chillies and allow to roast.
Once the dal starts to become golden, add onion and fry till translucent, about 1 minute. Add tomatoes, red chilli powder and salt and cook till tomatoes soften, about 5-7 minutes. Stir occasionally. Add water little by little if it starts to stick to the pot.
Once done, remove from heat and allow to cool to room temperature. Add it to a mixie jar along with freshly grated coconut. Grind to a coarse but wet chutney consistency. Add a little water if necessary.
Tempering
Add vegetable oil to a heavy bottomed pot and allow to heat up on medium flame. Add mustard seeds and allow it to splutter. Next add urad dal and chana dal and allow to roast. Once the dal starts to become golden, add dry red chilli and curry leaves. Fry till fragrant and curry leaves are crunchy.
Remove from heat and add it on top of the chutney. Mix well right before you serve.