Fry the ginger and cumin seeds with the onion. Add the poppy seeds, fry a little more, and add the turmeric, coriander powder, garam masala, chilli powder and tomato puree.
This is also cheaper in the long run than buying ready made curry paste although the initial outlay on the spices can be much less if you buy reasonable sized amounts from an asian grocery or "continental food store" as they call them here on Tyneside!
By the way, this is a great recipe Mr Falafel and we ate it in this amended form 3 weekends running!