Soak 1 cup kadala overnight. Drain the water and rinse the kadala 2-3 times. Pressure cook Kadala with 2.5- 3cups water and salt. I cook it for 8-10 whistles on, high flame. Switch off the gas and let the pressure drop completely, around 15 mins.
Grind together ingredients from chilli powder - chopped ginger and garlic with 2-3 tbsp water to a somewhat smooth paste.
Heat oil (1-2 tbsp) in a wide pan. Add sliced onion and cook till onion becomes a dark brown colour.
Add the ground paste and cook till the raw smell goes, 3-4 mins. Add 1-2 tbsp hot water to bring the masala together.
Add chopped tomato and salt. Cook till tomato softens.
Add chopped coriander leaves and mix well. Add tomato ketchup and soy sauce and mix well.
Add cooked kadala along with the cooking water. Bring it to boil. Reduce flame to the lowest, cover and cook till the gravy thickens around 10-12 mins. Let the curry rest for half an hour for the flavor to settle in.
While serving add some chopped onion as garnish.
Notes
Though I used coconut oil, you can use any veg oil for a more neutral taste. Also, you can crush some of the cooked chickpeas and add to the cury for a different texture and consistency. Please note that the gravy tends to thicken well as it rests, so adjust the consistency accordingly. It's almost a semi dry dish where the chana pieces are coated well with the gravy.