Combine the besan, yogurt, chopped green chilly, grated ginger, salt, turmeric powder with water and mix it well.
Take a sieve and put the bowl under the strainer now strain the besan mixture so that it becomes smooth batter (lumps free) and discard chopped chilly and grated ginger.
Now put the besan/gram flour mixture in a microwave safe bowl and cook uncovered in the microwave on high for 2 minutes.
Take out from microwave after 2 minutes and stir to break up any lumps.
Microwave it on high again for 1 1/2 minutes.
Remove from microwave and stir with the help of wired whisk to remove lumps.
Microwave again for last 1/2 minute and stir with the help of wired whisk.
It takes 4 minutes to get the gram flour/ besan mixture cooked.
Once the batter is done take out from the microwave and work fast as the batter solidifies when it’s cool down and it will become difficult to spread and you don't get thin layers in the roll so keep your thali or board or kitchen counter top ready while batter is cooking in microwave.
To spread the mixture I have taken the back of large steel thali. You can also use the back of a large baking tray, your kitchen counter top or boards to spread the mixture. No need to grease the thali with oil.
Quickly pour the khandvi batter on a large thali and spread it over thali very thinly and evenly with the help of scrapper. You can also use flat spatula or flat base vessel to spread the khandvi mixture. Once the thali is completely covered use the next thali for spreading the mixture. Don’t wait you have to be quick with the remaining batter too.
Let the batter rest for 2-3 minutes and allow it to cool down completely.
With a sharp knife, cut into long and 1 to 1 1/2 inch wide strips in the solid batter.
Carefully lift the edge and roll out each strip tightly from one end to another end to form cylindrical rolls. You can make the rolls as big as you like. Keep aside.
If you are getting large rolls in this case just cut horizontally and make a second roll.
Arrange the khandvi rolls in a plate or tray.
Heat oil in a small pan, once the oil becomes hot add mustard seeds and let it crackle. Now add few curry leaves, dry red chilly and switch off the flame.
Pour seasoning over the khandvi rolls evenly.
Garnish with freshly chopped coriander leaves and freshly grated coconut.
Serve at room temperature with any green chutney as per your taste.
You can serve this along with mint chutney or any other chutney or sauce as per your need and taste.Use green chili as per your taste.Sprinkle coconut and coriander leaves.Serve hot.