Heat up a pan on medium heat, once hot, add oil. Once the oil is hot, add cumin seeds. Saute for about 30 seconds.
Add the red onions and season with a little salt. Saute for about 2 minutes until the onions are translucent.
Now add the cubed potatoes and season with a little salt. Stir and cook the potatoes for about 4 minutes.
Now cover with a lid and cook on low flame for 5 minutes. The steam will cook down the potatoes.
This is what you should have.
Now add the bell peppers and season with a little salt.
Stir for a minute.
Now season with basic Indian spices - coriander powder, turmeric powder, red chili powder, and Kashmiri red chili powder.
Stir well.
Add a quarter cup of water.
Stir. Cover and cook the shimla mirch sabzi on low heat for about 10 minutes. Check-in between to prevent the dish from burning.
Check your sabzi. The potatoes should be fork-tender. If there is anything sticking to the pan, add a couple of tablespoons of water and stir.
Garnish with mango powder (amchur).
Your dish is ready! Enjoy with roti or plain paratha.