It's new variation to normal khatta and khaman dhokla as here I'm using both the batters to give a twist and in center using green chutney and that's why it's called three layers dhokla!
First for white Dhokla layer take 2 cups of idli rice and 1 cup udad daal separately into two different bowls and wash it properly.
Now add fenugreek seeds into the udad daal.
Rest both for overnight and grind it into mixture jar in morning.
Now put it into warm place of your kitchen for 5-6 hrs to get fermented.
Take this idli better into medium sized bowl and add 1 tsp of salt to make first layer.
Now grease the medium sized plate with oil.
Pour the first layer of idlis batter and put into already hot steamer.
Until first layer cooked, do preparation of third layer: For third layer, take 1 cup of chickpeas flour into medium sized bowl, add 1/4 tsp red chilli powder, 1/2 tsp turmeric powder, salt and sugar and mix it well.
Now add water to get desired consistency like idlis batter and mix it will using whisk to avoid lumps. Keep this aside.
Once first layer cooked after 7-8 mins, apply green Coriander mint chuteny and cook for 3 more mins.
Now add fruit salt into yellow chickpeas batter and mix it well and immediately pour that batter on top.
Sprinkle Chilli Powder on top and cook for 10 mins.
Once cooked remove it from heat and let it be at room temperature.
For tempering, add oil into small pan, add mustered seeds, once spluttered add asafoetida and green chillies and spread this tempering on Dhokla.
Cut them into triangle pieces and serve hot with red and green chuteny!