Wash and soak chana dal in an enough warm water for 4-5 hours.
Then add soaked dal into the grinder jar, add yogurt and blend smooth but slightly grainy.
Remove it into the mixing bowl, cover and keep aside for fermentation for 6-7 hours or overnight.
Once fermented well, add green chili-ginger paste, turmeric, hing, salt and oil. Mix it well and keep aside.
In a big pan or in a steamer/dhokla cooker, boil enough water, keep the stand in the center.
Grease the dhokla pan/tray inside with oil.
Now take the prepared batter bowl, add ENO soda, add 2 tbsp water over the soda, mix well the batter with spatula, batter will be foamy and soft.
Pour foamy batter immediately into the greased pan and put it into the steamer, cover with lid and steam it about 15-18 minutes on medium flame.
Insert knife in the center of steamed Khaman and check, if knife comes out clear that means it is ready, if not cover and steam it again for another 5-8 minutes.
Remove the pan from the steamer and allow it to cool down for 5 minutes, then cut it into square pieces. Remove the Khaman pieces into the big mixing bowl and keep aside.
For Tempering
Heat oil in a tempering pan add mustard and sesame seeds, once start crackling add hing, silted green chilies and curry leaves. Add water, salt, mix and let it boil.
Now pour hot tempering over prepared Khaman pieces, add chopped coriander leaves, grated fresh coconut, toss and mix gently.
Vati Dal Na Khaman Dhokla are ready, serve with green chutney and enjoy with cup of tea.