Roast the semolina on low flame till it becomes light golden and fragrant. Then remove semolina and keep aside. In the same pan, add 1 tsp oil and roast the vermicelli on a low flame till they become crisp and slightly golden brown.

Since I am using roasted vermicelli here, it took me less minutes to roast it. Then remove the roasted vermicelli from the pan and keep it aside. In a large bowl add roasted semolina, roasted vermicelli, curd and mix well.

For tempering, heat 1.5 tbsp oil in a small tadka pan over medium heat. Add mustard seeds, urad dal, asafoetida, green chillies, curry leaves, turmeric and saute till it splutters.

Add this tempering to the semolina-vermicelli mixture and mix well. Add chopped coriander leaves, salt and ½ cup water.

After 20 minutes add water to the idli steamer and let it boil. Grease the idli molds.

Add ½ teaspoon of baking soda to the semolina-vermicelli mixture before steaming. If required, then add 2-4 tbsp or more water as needed.

Mix well and then pour the prepared batter into the moulds. After the water boil, place the batter filled idli plate in the steamer and steam for 7-8 minutes. Insert a toothpick in the center of the idli, if the batter sticks to it, steam for a few more minutes until the toothpick come out clean.

Switch off the flame and take out the mould. After a few minutes, remove the idli from the mold with a spoon and transfer it to a serving plate.

Serve hot Semolina and Vermicelli idlis with coconut chutney or sauce.