Peel and cut sweet potatoes into slices. Keep them into water to remove excess starch and prevent from turning dark in color.
Heat oil in a non-stick pan or kadai. Add mustard seeds; when they begin to splutter, add cumin seeds and curry leaves. Sauté them for few seconds. Add chopped onions and garlic, stir-fry until onion becomes translucent.
Add green chillies and chopped tomatoes, cook over medium heat for 2-3 minutes.
Add sweet potatoes, turmeric powder, red chilli powder and salt.
Mix them and sauté for 2-3 minutes over medium flame.
Add 3/4 cup water and bring it to boil. Cover with lid and reduce flame to low.
Cook covered until sweet potatoes become soft and gravy turns thick or for around 8-10 minutes. Stir in between occasionally to prevent sticking and add more water if required.
Turn off the heat and let curry stand for 5 minutes.
Transfer it to a serving bowl and garnish with coriander leaves.
Tips and Variations:
- You can also use boiled or steamed sweet potatoes instead of using raw one. If you are using boiled one, then decrease water quantity to 1/4 cup in step-5.
- Add 2 tablespoons grated coconut in step-6 just before turning off the heat and mix well to make sweet potato curry with coconut.
Taste: Mild sweet and spicy with mellow and soft texture
Serving Ideas: Serve it with steamed rice or chapati.