Peel the outer skin and wash properly. Dice into equal size cubes.
Heat 1 tbsp oil in a pan. Add mustard seeds and let them splutter. Add chopped garlic and onion and saute till translucent. Add curry leaves and green chillies.
Add diced sweet potatoes, red chilli powder, coriander powder and saute for 3 minutes on medium high flame.
Add 1 cup of coconut milk and simmer for 3-5 minutes more. Or till they are cooked soft.
Turn off the gas and garnish with coriander leaves.