Peel potatoes and chop them in to 1/2 inch pieces. Immerse chopped potatoes in a cup of water and pressure cook till the pieces are soft.
Finely chop tomatoes, onion and coriander leaves. Make paste of ginger and garlic using mixer or mortar and pestle. Keep them aside.
Method
Add all the seasoning ingredients in to a pan in the order mentioned, when mustard seeds splutter add chopped onions. Saute till onions turn translucent.
Now add tomatoes and saute till tomatoes are mushy. Add ginger garlic paste, slit green chillies, jaggery and turmeric powder. Stir till all the spices blend with onion.
Now add cooked potatoes along with water, salt and garam masala powder. Saute well. Cook it for few more minutes and switch off. Garnish with coriander leaves.
Potato gravy is ready to be served as side dish for chapathi or poori.
Note
Add additional water to the gravy as per your preferred consistency.
Jaggery is optional, but I like right balance of all tastes in any dish. So I have added.