In a mixing bowl take besan, suji, sugar, citric acid, salt and soda and mix them well.
Grease the box or container with oil in which you are planning to make dhokla and keep it aside.
In 2 cups of water mix turmeric powder. Now in besan mixture add little water at a time and make a smooth batter.
Make sure to make smooth and flowy batter. In a steamer or pressure cooker heat 2 -3 cups of water and bring it to boil. The amount of water to be added depends on the size of steamer or pressure cooker.
Now add fruit salt (eno) to the batter and brisk quickly. Friut salt should be mixed evenly or else you will give uneven dhokla after cooking.
After adding fruit salt batter will become frothy and bubbly.Pour the batter in a greased container. Dhokla is ready to be steamed.
For steaming khaman dhokla:- If using pressure cooker put small steel ring or bowl in cooker.
Place the container in the cooker. The water should already be boiling or hot when you put the pan / container in cooker.
Remove the whistle/ weight from the lid and close the pressure cooker tightly. Steam it for 20 -22 minutes on medium high flame. Then switch off the heat and to check the doneness insert a tooth pick in dhokla. It should come out clean if dhokla is done.
If it has batter on it steam the dhokla for some more time. If dhokla is done take it out and let it rest till it becomes warm.
In a meanwhile take a pan and heat 2 tsp oil in it. As the oil gets hot add cumin, hing, til, and saute for a minute.
Now add slit green chilli, mustard seeds and let mustard seeds splatter. Now add 2 cups of water, sugar and salt and let the tadka come to boil.
Switch off the heat and let the tempering mixture become warm (not cold) before using.
For assembling dhokla:- When dhokla becomes warm take sharp serrated knife and gently slide along the edges. Cut dhokla in pieces.
Now with the help of ladle pour half of the tempering water such that it seeps in through the cuts and sides of the dhokla.
After ten minutes pour another half of water and let the water get absorbed. Carefully remove the pieces on serving plate.
Garnish with grated coconut and fine chopped coriander leaves. Enjoy khaman dhokla with green chutney or imli ki chutney.