Chop the ginger, garlic, and green chilly. Chop the onions and green peppers.
Heat a pot on medium heat, add oil, add the spices... cumin seeds, kalonji seeds, hing, and turmeric powder. Cook for about 30 seconds.
Add ginger, garlic, and green chilly. Stir and cook for a minute.
Add onions. Stir. Allow this to cook for about 4-5 minutes.
Chop the green pepper.
Add the green pepper and saute for about 4-5 minutes on medium heat.
This is what you should have.
Add tomatoes and tomato paste.
Cover and cook on low heat for 10 minutes. Keep stirring in between.
Add coriander powder and red chili powder. Stir and cook for 20 seconds max.
Add the cubed potatoes. Stir.
Now add water. Season with salt if need be.
Cover with a lid and cook for 20 minutes on low-medium heat. The potatoes should be fork-tender, if not, cover and cook for another 5-10 minutes.
Once done, this is what you should have.
Add dry fenugreek leaves and garam masala. Stir.
Serve with roti.