Take the yogurt in a bowl. Add water and stir well till smooth.
Add ginger-green chili paste, turmeric powder,asafoetida and salt.
If using fresh yogurt, then to add the sourness, add about ½ tsp of lemon juice.
Add the gram flour/besan. With a wired whisk, keep on stirring and mixing till all the lumps are dissolved and you get a smooth batter. There should be no lumps in the batter. You can also use a hand held beater to mix the batter.
Spread oil on plates or boards or tray. Large steel lids or thalis work very well. You can also use the back of a large baking tray or your kitchen counter top.
Also mix the chopped coriander leaves and grated coconut. Keep aside.
Pour the batter in a sauce pan or a broad frying pan. Switch on the stove top and keep the flame to the lowest. Begin to stir.
Keep on stirring when the khandvi batter is getting heated up. Lumps begin to form and you have to continuously stir so that the lumps don't form.
The batter would thicken and keep on thickening. Keep on stirring. Best to use a wooden spatula or a heat proof silicon spatula.
The batter also should not be allowed to stick atthe bottom. So you have to stir continuously
Do a plate test when the batter has thickened well.
Spread a few teaspoons of the batter on a greased plate. Let it cool a bit and then begin to roll. If you are unable to roll, then the batter needs to be cooked more.
The final consistency of the khandvi batter is shown in pic 17 below. It took me 17 minutes to get the correct consistency on a low flame. The timing will vary depending on the intensity of the flame, the thickness/thinness of the pan and the size of the pan. Just do the plate test and when you can form the rolls, then the khandvi batter is ready. If the batter becomes too thick, then it becomes difficult to spread and you don't get thin layers in the rolls. In this case, still spread the batter. You will get thick slices, but still they taste good.