Soak the cashew nuts in warm water for about 15-20 minutes.
Wash the potatoes thoroughly, then using a fork or a knife(be careful), prick the potatoes so they cook evenly.
In a wok, heat some oil, when the oil is hot, fry the potatoes till they are brownish and crisp. Transfer the potatoes onto a kitchen and get rid of any excess oil.
Drain the water from the cashew nuts, and blend the cashews to a smooth paste and keep aside.
In a bowl, whisk the yogurt, add to it the cumin powder, fennel powder and red chilli powder.
In a pan, heat oil, once oil is hot, add the finely chopped onions. Sprinkle a little salt, stir well and cook the onions until they go soft.
Add in the chopped ginger and garlic, stir well.
Now add in the yogurt mix, and stir well. Now add in the cashew paste and stir everything well.
Add in the whole spices – caraway seeds, ground cardamon, black peppers and cinnamon.
Now add in the fried potatoes, stir everything well.
Add a little bit of water, stir, cover and cook for about 15 mins or until the potatoes are cooked on low heat, checking every 5 mins or so and stirring.
The curry should thicken, however add water and seasoning based on how thick you like your curry to be.
Once cooked, garnish with coriander and crushed fenugreek leaves (optional) and serve with hot rotis or steamed basmati rice.