Dry roast the oats for 2–3 minutes in a pan until lightly aromatic. Set aside.
Heat oil in a non-stick pan. Add mustard seeds, curry leaves, ginger, and green chilli.
Add chopped onions and sauté until translucent.
Add all chopped vegetables and sauté for 2–3 minutes.
Pour in water and let it come to a boil.
Add the roasted oats gradually while stirring continuously to avoid lumps.
Add salt, cover and cook for 4–5 minutes on low flame until soft.
Turn off the heat. Add lemon juice and garnish with fresh coriander.