Heat 3 tablespoons oil in a pan or kadai. Add ½ teaspoon finely chopped garlic and saute for a few seconds. Add the diced onions. Sauté until translucent.
Next, add one cup of chopped tomatoes. Mix very well.
Cover the pan with its lid and simmer on a low heat until the tomatoes soften and become mushy. Do check a couple of times when the tomatoes are cooking
Add ½ teaspoon turmeric powder, 1 teaspoon kashmiri red chilli powder (or ½ teaspoon regular red chilli powder or cayenne pepper), ½ teaspoon coriander powder, ½ teaspoon garam masala powder and ½ teaspoon cumin powder (optional). Mix very well.
Then add diced potatoes (4 medium sized potatoes, diced). Also season with salt as required. Mix very well.
Pour two cups of water and stir well. Cover the pan with its lid and simmer on a medium to medium-high flame until the potatoes are cooked.
Then switch off the heat and add ¼ cup chopped coriander leaves (cilantro). Mix very well.