500g dried chickpeas/chana, or red kidney beans (for Rajmah). Soak overnight, boil with 1/2 tsp salt for 1 hour or until they mash between your fingers. Save chickpea water.
4 medium onions, finely chopped
1 1/2 tsp ginger garlic paste
4 medium tomatoes, pureed
4 serving spoons oil
1/4 tsp turmeric
1/4 tsp red chili powder
1 tsp coriander powder
1 tsp salt
2 tsp chana masala (only for chana, not rajmah. it's a little sour due to mango powder.)
1/2 tsp garam masala
2 tsp fenugreek leaves

1. Heat oil. Add chopped onions, cook 8-10 minutes on high
2. Add 1/2 cup chickpea water, then ginger garlic paste, cook 2 minutes
3. Add all spices, 1/2 cup chickpea water, cook 2 minutes (add the beans now too, I think?)
4. Add tomatoes, cook 2-3 minutes
5. Garnish with fresh onions, tomatoes, and ginger, serve as Chana Masala.
Or
5. Add 2 cups chickpea water, cook 2 minutes, mash a bit, cook 10 minutes, and serve as Choley.

Source: Nisha at Taste of India cooking class, McLeod Ganj, India