In a frying pan add 1/2 tea spoon of oil, palak leaves and cumin seeds. Fry them in medium flame till the spinach leaves become mushy.
Add fried items from step 1, grated coconut, green chilly and salt in to a blender and grind it to fine paste adding minimum water.
Now transfer this in a bowl, add whisked curds/butter milk and mix it well. The consistency of tambli should be thinner than chutney. So adjust the consistency by adding water.
Now in a seasoning pan heat oil, add mustard seeds, urad dal, red chilly and curry leaves. When mustard seeds splutter add it to tambuli. Palak tambli is ready to be served with hot rice.