Heat cooking oil in a karahi. Add cumin seeds and when cumin seeds splutter put grated ginger and saute for 30 seconds. Add garlic paste and saute for 30 seconds and then add chopped onion and cook till onion gets translucent. Now add grated tomato and cook till oil leaves the karahi. Mix salt, red chilli powder, turmeric powder, garam masala and chana masala and mix.