Boil potatoes in salted water. Remove peels. Prick them with fork.
Heat oil in a Kadhai. Add potatoes. Saute until light brown.

Grind onion, cashews, garlic & ginger in a mixer grinder. Grind tomatoes & green chillies separately.
Heat oil in a Kadhai. Add onion paste. Saute until it leaves Kadhai.

Add tomato paste. Saute all. Once Masala leaves oil. Add red pepper, turmeric powder, coriander powder & salt. Stir well..

Add curd or milk cream.

Mix well. Add 1 cup water. Once it boiled.Add potatoes add Garam masala. Cook it for 4-5 minutes. Check seasonings.
Switch off gas.

Garnish with coriander leaves. Serve with chapati or naan.