Heat oil in a heavy bottom wide shallow pan.
Once hot, add cumin seeds and mustard seeds.
Once they are done popping and cumin seeds turn deeper in color and release the aroma, add a pinch of asafetida, curry leaves, chopped thai green chilis, sliced garlic and sliced onions along with 1 tsp salt.
Mix it all well and keep sauteing on medium heat until the onions are translucent but still hold its color, sure they do no turn brown.
If using boiled potatoes, Add boiled cubed potatoes along with ¼ cup of water. Mix well.
If using uncooked potatoes, add peeled and cubed uncooked potatoes to the pan. Add tiny amount of water (2-4 tbsp), mix well and cover it. Keep cooking on medium heat while it is covered until potatoes are fork tender.
Add all dry spices, salt (1 tsp if adding sugar, ½ tsp if skipping sugar) and sugar.
Mix it gently until all the potatoes are evenly coated with the spices. Cook for 2-4 minutes on low/medium heat.
Cover it for a minute or two and cook on medium heat,
Take the lid off, add chopped cilantro and mix well gently.
Take it off the heat and serve it hot with side of phulka rotli, gujrati dal and bhat!!