Boil the potatoes till they are soft. I cooked in a pressure cooker for 4 whistles.
Take out the skin and roughly mash it and keep aside.
Grind the tomatoes, ginger, coriander seeds and ½ tsp cumin seeds into a fine paste.
In a pan add oil and add ½ tsp of cumin seeds.
Once it starts crackling, add the ground tomato paste to this.
Add turmeric powder, red chili powder and salt to this.
Mix well and cook this for 2 minutes.
Now add the potatoes.
Mix well and add 1 cup of water.
Cover this and cook for 5 -7 minutes.
Stir in between.
If you feel the gravy is thick, add little more water and boil for a minute.
Switch off the flame.
Garnish with finely chopped coriander leaves.
Serve with chapati or poori or jeera rice.