Heat a wok or a kadai and roast the vermicelli for 3-4 minutes until slightly golden. Transfer to a plate and keep aside.
Heat oil in the same kadai and add urad dal, mustard and cumin seeds. Let them crackle for a minute and add the chillies and curry leaves. Saute for 1-2 minutes and add the onions. Mix well.
Add turmeric powder and salt and saute for 1-2 minutes. Then add the vegetables and stir well. Allow them to cook for 3-4 minutes.
Add the tomato puree and 2 1/2 cups of water, and bring to a rolling boil. Add the vermicelli and mix well. Cover the kadai with a lid and let it cook for 5-6 minutes or until the vermicelli is cooked and the water is dried up.
Check seasoning. Transfer to a serving bowl and finish with roasted peanuts on top and a fresh green chilli. Serve immediately.