Heat oil in a pot over medium heat and add the mustard, fenugreek and cumin seeds. Let them crackle and then add the dried red chilies.
Turn down the heat and add the red chili powder, turmeric and cumin powder. Mix and make sure the spices don't burn.
Quickly add in the boiled potatoes and stir well, making sure the potatoes are nicely coated.
Season to your liking and finish up with some Kasoori Methi (lightly crushed between your fingers) and lots of lemon juice.
Give it a final mix and take it off heat. Top with chopped cilantro and serve!
Notes
Turn down the heat once you add the whole spices into the oil. They can burn pretty quick, and will end up tasting bitter!
Taste as you go- especially if you're using dried fenugreek leaves for the first time! Start with a little, and then add more if you want to.
For some extra flavor, sprinkle my homemade chaat masala over it, right before serving.
If you added too much of the dried fenugreek leaves, and the stir fry tastes bitter, add some jaggery to balance out the flavor with some sweetness. And of course, don't forget the lime juice too.