Wash potatoes and pressure cook them with just 1/4 cup of water until one whistle. If you do not have baby potatoes, you can still cut big potatoes into 4 pieces and use it. Now peel the skin and prick them with the help of a fork. If they are pricked nicely, they will be lighter after getting fried.
Now in a frying pan, heat mustard oil. When the smoke comes out of it, add some boiled potatoes and fry them until golden brown in colour on medium heat. Fry all the potatoes in the same way.
Now take 2 tablespoon of water in a bowl and add 1 teaspoon of red chilli powder to it to make a paste. Now take yoghurt and add red chilli powder, ginger powder and fennel powder to it and mix it very well. If you want to add plain flour or gram flour in the yoghurt, you can add it at this stage so that there is no fear of split curd later on.
Heat 3 tbsp oil in a pot. Add cumin and hing to it. Now add all the whole spices and saute it for a minute. Now put the flame on low and add chilli powder paste to it. After 1 minute, add yoghurt mixture to it and mix it very well. Keep the flame low and keep on stirring otherwise the yoghurt will split. You can even turn off the heat while putting the yoghurt.
Keep on stirring the gravy until oil separates. Now add fried potatoes to it along with one and half cup of water. Cover and cook dum aloo for 10 to 15 minutes until the gravy thickens.
Serve hot dum aloo with pulav and paratha.
