Heat oil and add cumin seeds
Once the cumin seeds start to burst add the onion, curry leaf and chillies
When the onion is transluscent add the potatoes and turmeric. Season with salt
Saute the potatoes on low heat for about 2-3 minutes. Add half cup of water and simmer on a low heat until the potatoes are soft and tender. During the cooking process you can add a little more water if it dries out before the potatoes are cooked
Mix in the mint and coriander and serve hot