Ingredients
3 medium sized potatoes, boiled and cubed.
2 medium tomatoes, cut into medium sized cubes
1 tsp jeera
1/2 tsp cumin powder
1" piece ginger, finely minced
1/2 tsp turmeric
3-4 green chillies, split
1 tsp chilli powder
2 onions sliced
2 tsps of coriander leaves, chopped
2 tbsp oil/ghee(clarified butter)

Method
Heat the oil  and add the jeera and onions.
Fry till the onions turn translucent.
Now add the green chillies and keep frying till the chillies 
turn color.
Now add the remaining spices and fry for a minute.
Add the tomatoes and fry for 3 minutes.
Add the potatoes and salt.
Add one cup of water and cook on a low flame, covered for 10 minutes.
Just before taking the dish off the fire add the chopped coriander leaves.
Goes very well with puris.