In a bowl, add the yoghurt, turmeric, garam masala, pinch of cumin seeds, gram flour and water. Whisk together until smooth.
Heat the oil in a medium sauce pan. Add the cumin seeds, mustard seeds, curry leaves, salt and garlic ginger. Stir through
Next add the blended tomatoes and green chillies to the pan, and stir through. Let this simmer for 20 minutes on low heat. You will need to add splashes of water as the masala dries out.
Then add the yoghurt mixture and stir through. Allow this to simmer on very low heat for an hour or until the karhi has thickened. You will know it is done when you see the oil separate from the yoghurt mixture.
Garnish with the fresh coriander and then serve with plain white basmati rice or chapattis.
Video
Notes
I've not added a tarka to the recipe, as I think the flavour is amazing as it is. But if you want to add tarka, just fry a sliced onion with a tablespoon of curry leaves and combine with the kadhi after step 4. Stir through then proceed to step 5.
Kadhi or karhi has to be served with vegetable pakoras. Search vegetable pakoras or see the link in my blog for the perfect vegetable pakora recipe. You can make the pakoras whilst the yoghurt mixture is simmering on low heat to save time.
Add the pakoras just before you are about to serve. Don't add them too soon, as they longer they sit in the kadhi, the softer/soggier they become.
The kadhi thickens as it cools down. So if you are eating this later in the day, or even the next day, add a bit of water when reheating.