Firstly, in a bowl, add 1 cup sooji, ¾ cup curd, and mix well. Add ½ cup water and mix. Cover and rest for 15 minutes.
For onion tomato chutney, add 1 tbsp oil in a pan and heat it.
Add 1 tsp mustard seeds, 1 tsp jeera, ¼ tsp asafoetida, 2 dry red chilli, 10 curry leaves, and keep the flame on medium.
Add 2 roughly chopped onions and cook for 2 minutes.
Add 1 tsp each chopped garlic, ginger, green chilli, and keep stirring continuously.
Add 2 roughly chopped tomatoes and cook for 2-3 minutes.
After it is perfectly cooked, turn off the flame and let it cool.
Transfer it to the mixer jar, add ½ tsp salt, and grind it. After grinding, transfer it to a serving bowl.
After 15 minutes, the water is completely absorbed.
Add 3 tbsp each chopped capsicum, carrot, onion, coriander, and combine everything well.
Add ½ tsp salt, ¼ tsp red chilli powder, 1 tsp oregano, 1 tsp chopped green chilli, and mix well.
Take a microwave-safe idli maker and add some water for steaming.
Add 1 tsp ENO and 1 tsp water to it to activate, and then gently mix.
Now, fill 1 tsp batter in the idli mould, arrange the moulds one over the other, cover and microwave for 4 minutes.
After 4 minutes, soft and spongy idlis are ready.
Finally, enjoy vegetable idlis with onion tomato chutney.