In a large pot, add the peeled and chopped potatoes, whole tomatoes (slit) and the green peas. Add about 3 cups of water, or enough to cover the vegetables and place it on medium heat. Let the vegetables cook. After about 1—12 minutes, you will notice that the potatoes are cooked and the tomatoes are soft.
At this stage, remove the tomatoes using a slotted spoon and transfer it to a blender. Also drain the cooked vegetable water in a bowl and keep aside.
In a kadai or a wide pan, heat the oil. Add the cumin seeds and let it splutter. Now add the turmeric powder and the red chili powder and mix well.
Add the drained water to the pan and let it come to a quick boil.
Next add the cooked vegetable and salt and mix well.
In the meantime, blend the cooked tomatoes in the blender and make it a puree. Add this puree as well to the vegetable and let it cook further, covered, for about 6-8 minutes.
Serve hot with Puri/Poori!