Heat the oil in a heavy-bottomed pan over medium heat.
Add the mustard seeds. 2.
Once the seeds begin to pop, immediately cover the pan.
When the popping stops (about 1 minute), remove the lid. 3.
Add the diced onion and turmeric.
Sauté for about 5 minutes, until the onion is soft and translucent. 4.
Stir in the cubed potatoes, water, and salt, ensuring everything is well-coated. 5.
Cover the pan, reduce heat to low, and simmer for 20 minutes, or until potatoes are tender.
Add a splash more water if the pan looks dry to prevent sticking.
Don't walk away when heating the mustard seeds! They can burn in seconds. Be ready with the onions as soon as the popping subsides.