Batter: Add jowar flour, suji and curd to a mixing bowl. Add water gradually and make a thick and fluffy batter which has the consistency of cake batter. It should fall in a ribbon like consistency when poured with a ladle. Rest the batter for 15 minutes. Then add crushed ginger and green chillies, 1 teaspoon oil & salt and mix well.
Prep Steamer: Grease a round 12 inch plate with oil. Heat the steamer or a pot with water. Place a stand inside and let the water come to a boil.
Add Fruit Salt or Eno: Once the water starts boiling, add fruit salt or Eno to the batter, and mix gently till the batter is frothy.
Steaming Dhoklas: Transfer the batter immediately to the prepared tray or plate, keep it on the stand, cover and steam on medium low heat for 15 minutes. To check if the Dhokla is cooked, insert a toothpick in the centre of the dhokla and if it comes out clean, it's done. If it has batter on it, steam for a few more minutes until done. Remove the plate from the steamer and set aside to cool.
Tempering: Heat oil in a pan, add mustard seeds and once they sputter, add sesame seeds, hing, curry leaves, salt, sugar and water. Be careful as the water will splutter. After 10 seconds, switch off the stove and squeeze lemon. Mix with a spoon.
Serving Dhoklas: Demould dhoklas once cooled and cut into squares. Pour the tempering over the dhokla and let it soak in it for 5-10 minutes. Garnish with grated coconut & coriander leaves just before serving. Dhoklas are ready to be served with green chutney.