Wash and soak the chickpeas overnight. Cook the chickpeas in pressure cooker with a pinch of salt. (some chana masala powders have too much salt)
Once the chickpeas are cooked, add chana masala powder and cook on slow flame for 15 to 20 minutes. Add salt if needed.
Heat oil in another saucepan. Add ajwain seeds, whole cumin and grated ginger. Fry for 10 seconds and add chopped onion and fry till light golden.
Then add 2 tsp coriander powder, black pepper powder and 1 tsp chili powder and fry for 1 minute on low flame. (Keep a close look as the spices might burn.)
Add the cooked chickpeas along with all the liquid to the fried onion. Cover and cook on low flame for 30 to 40 minutes till the water is reduced slightly with a nice gravy like texture.
Check the salt and spice and adjust accordingly. If you want more spicy, then add more black pepper powder.
Serve hot with puri or paratha.