Heat ½ cup oil in a pan. Add chopped onions and sauté until golden brown.
Add cumin seeds and black cardamom. Mix for a few seconds.
Add ginger-garlic paste and cook until the raw smell disappears.
Add blended tomatoes and cook for 2-3 minutes.
Now add red chilli powder, crushed red chillies, salt, turmeric powder, and coriander powder. Mix well and cook until the oil starts to separate.
Add the cubed potato and mix it properly with the masala.
Add 1 cup water, cover the lid, and cook until the potatoes are half done.
Open the lid, add boiled chickpeas, and mix well.
Add 1 cup chickpea water or regular water. Cover and cook on low flame for 10 minutes until the curry becomes flavorful and slightly thick.
Sprinkle garam masala, fresh coriander leaves, and green chillies on top.
Chanay Aloo are ready to serve.