Take yogurt in a bowl and whisk well. Now add chopped ginger, semolina and approx. a cup of water and make a medium thick batter ,slightly thinner then the normal idlis
Whisk well and add salt,corn kernels and a pinch of turmeric.
Cover and rest for 15 minutes .
Make the tempering-heat oil in a small pan,and fry cashew pieces on low heat till golden in colour,remove from the pan and add them in the semolina mixture
Now in this oil add mustard seeds and white lentils,when it start crackling,add curry leaves pieces and asafoetida and remove it from the flame.
Add dried fenugreek leaves (kasoori methi), saute for few seconds and mix in the semolina batter.
You can add some more water in it ,if it thicken a bit now.
Heat water in a steamer and grease the idli plates with oil.
When water start boiling add fruit salt in the mixture ,mix well and pour approx 1 tbsp of mixture in every idli mould.
Place the idli stand in the steamer ,cover and cook for approx.10 minutes ,first on high heat and then on medium flame .
Remove the steamer from the flame,let it stand for 5 minutes and then with the help of a greased spoon scoop out the idli’s .
Serve hot with sambhar and coconut chutney.