Wash sweet potatoes, peel the skin and slice them and add to salted water. To make salt water add ¼ tsp salt to 3 cups water. Keep them in water for at least 15 mins.

Add oil to a non stick and heat. Add mustard and cumin.

When they begin to splutter, add grated ginger & curry leaves. Fry until the ginger smells good.

Add the onions and fry until lightly golden. Drain the sweet potato slices and add them to the pan. Sprinkle turmeric.

Fry for about 3 to 4 minutes on a medium heat, stirring often.

Cover and cook on low flame till the sweet potatoes turn soft. Stir occasionally to prevent burning.

When the sweet potatoes are cooked fully, sprinkle salt, red chili powder and garam masala.

Fry till the masala smells good and is blended well. You may add little more oil at this stage if the spice powders don't blend well. Do not over fry the sweet potatoes.

Garnish with coriander leaves. Serve sweet potato stir fry with rice and rasam.