Heat oil in a cooker, add ground masala to it along with the curry leaves. Saute for 2 -3 mins then add all the dry masala powder and salt and a little water. Cook till the oil leaves sides.

Then add the matar, potatoes and tomatoes and mix then add 2 cups water and cover lid and let it cook for 4-5whistles. When the pressure is released mash with a wooden hand blender and mash the potatoes roughly.

Chatpati masala: in a pan add the cumin seeds, coriander seeds and red chillies, roast for 5 mins on low flame till it starts releasing it's aroma. Cool and blend to a fine powder. You can store this powder in an airtight container for all chaat items.