Gently wash and drain the rice around 5 times in cold water. This will help to remove some starch and give you perfect fluffy rice. Leave the rice to soak in a bowl of cold water for 30 minutes and drain before you need to use it.
Boil the potatoes in salted water until al dente with 1/4 tsp turmeric added for colour.
Heat the ghee in a large non-stick pan (one with a lid). Add the cumin seeds, curry leaves and peas. Saute for a few minutes then add the rice. Combine gently until the rice is coated in the ghee and spices.
Add around 700ml boiling water, 2 tsp salt and the boiled potatoes. Bring to the boil. The water should come up about 1/2 an inch to an inch above the surface of the rice.
Turn the heat to low/medium and cover the entire surface of the rice/water mixture with a piece of foil. The foil should just sit on top of the contents of the pan so that the steam doesn't escape.
Cover the pan with a lid and leave on a low/medium heat for 10-15 mins. I would suggest checking the rice after 10 minutes. If it is almost, but not quite done, turn the heat off and put the foil and lid back on for a further 5 minutes. The rice should finish cooking perfectly in the steam.
When your rice is cooked, allow it to cool for 5 minutes and then gently separate the grains with a fork and serve with soups, stews or curries.