Place in a medium pressure cooker/ saucepan and add the water, coconut milk, turmeric powder, salt, dalchini/cinnamon, tomatoes, and green chillies and curry leaves.
Pressure cook.
Preparing the Tadka:
In a kadhai/wok, heat the ghee or oil on high heat till just beginning to smoke.
Add the mustard seed and cover with a cover to prevent splattering.
Once the seeds have crackled add the onions, garlic, curry leaves and the dried red chillies.
Reduce the heat to medium and fry till the onions turn a golden colour. Take care as the tadka may burn.
Add the lentil mixture to the sautéed spices and allow to simmer gently for a couple of minutes.
Add lime juice and adjust the seasoning with salt. The lentil or dal curry is ready to be enjoyed as an accompaniment to rice.