Heat oil in a non-stick frying pan or skillet over medium-low heat.

Add pureed onions, tomatoes, ginger paste, and garlic paste to the hot oil.

Cook for about 2-3 minutes until the onions turn translucent.

Stir in cumin powder and coriander powder.

Cook for another minute until the spices are fragrant.

Add cubed potatoes and sliced green bell peppers to the pan.

Mix well with the onion-tomato-spice mixture.

Sprinkle turmeric powder and chili powder over the vegetables.

Stir to coat the vegetables evenly with the spices.

Pour in 1/2 cup of lukewarm water and stir to combine all the ingredients.

Season with salt according to taste.

Cover the pan and let the curry cook for about 15 minutes on medium-low heat, stirring occasionally, until the potatoes and peppers are tender.

Once the potatoes and peppers are cooked to your liking, remove the pan from the heat.

Garnish with chopped cilantro/coriander leaves.

Serve hot as a main course, accompanied by rice or Indian flatbread.