In a large bowl, gently toss the diced, boiled potatoes with ½ teaspoon of salt, making sure to separate any pieces that are stuck together. Prepare all your other and have them ready by the stove; this dish comes together very quickly.
Place a medium nonstick frying pan over medium-high heat and add the oil.
Once the oil is hot and shimmering, add the asafetida. A second later, add the urad dal. Watch closely, and as soon as the dal begins to turn a light golden brown, add the mustard and cumin seeds.
When the mustard seeds begin to pop, immediately add the fenugreek seeds, followed by the crushed curry leaves and green chilies. Be careful, as the curry leaves will splutter loudly. Give everything a quick stir and add the sliced onions.
Sauté the onions, stirring frequently.
When they start to show a hint of browning at the edges, add a tablespoon of water to the pan to deglaze it.
Repeat this process two more times, cooking the onions for a total of 7–8 minutes until they are soft and sweet.
Stir the sugar and a small dash of salt into the onions.
Add all the salted potatoes to the pan, along with about ½ cup / 120 ml (4.1 fl oz) of water.
Stir gently to combine everything.
Reduce the heat to very low, cover the pan, and let it simmer for 10 minutes, stirring occasionally. The goal is for some of the potatoes to break down and melt into the water, creating a light, creamy sauce.
Once cooked, garnish generously with fresh cilantro and serve immediately.
When adding curry leaves to hot oil, stand back as they will pop and splutter. Crushing them in your hand just before adding helps release more of their aroma.
