Now, take a kadhai or a cooking pan and add mustard oil.
Let the oil heat until it smokes a little. Keep the flame on medium.
To this, add the dried red chilis (break them from the middle), bay leaf (tear it from the middle), green cardamom, cloves, cinnamon, and 2 pinch of cumin seeds.
Stir everything well until the aromatics start to release the fragrance.
Now, add the turmeric and Kashmiri red chili powder.
Stir consistently and fry them for 15-20 seconds. This will impart a beautiful color. Be mindful not to burn the spices.
To this, add the spice slurry made before.
Combine and cook until they are a bit brown or the raw smell of the spices is gone.
Now add the tomato puree and combine well.
Stir and fry them until the masala starts to release oil.
While they are getting fried, take a bowl and add the sour curd or yogurt. Add a bit of salt and sugar.
Whisk until the sour curd is smooth and creamy.
Pour this mixture into the masala and combine nicely.
As soon as you pour the curd into the kadhai, immediately start to stir the masala vigorously. This will prevent the curd from splitting.
Stir and cook this for about 5 minutes.