In a Kadai, bring water to boil and add salt. Then add the veggies and the moong dal. Cover and cook until the veggies are soft and tender. Discard any remaining water. Strain and keep aside. Try to use minimum water to cook vegetables so that you don't have to throw away.
Dry the pan and in the same pan, add coconut oil and keep it on medium flame. Once it becomes hot, add the mustard seeds and let it splutter. Then add curry leaves, dry red chillies, channa dal and urad dal. Keep stirring until the dal turns golden brown.
Thengai Poriyal - South Indian style vegetable side dish https://www.themagicsaucepan.com/main-course/veggies-poriyal/beans-poriyal-stir-fry