Cook Chickpeas: Soak chickpeas in water for 2 hours, then boil until soft.
Prepare the Curry Base: Heat oil in a pan, add mustard seeds, chopped onion, and salt. Saute until onions turn transparent.
Add Spices and Tomato: Add turmeric powder, ginger garlic paste, green chillies, and tomato puree. Cook until moisture evaporates.
Add Chole Masala: Stir in chole masala powder, a pinch of black salt, and the boiled chickpeas with water. Cook to a slightly thicker consistency.
Garnish and Serve: Finish with chopped tomatoes and coriander leaves. Serve hot with pooris.