Chop the onions and tomatoes into large chunks like you would for any Indian curry.
Start with some oil in a pan and once the oil is considerably hot, sauté the onions first on a low-medium flame until golden brown and caramelized. Add the Ginger-garlic paste and sauté for a minute.
Add in the tomatoes. Cook until the tomatoes disintegrate and are cooked completely. They should be easily mashable with the back of the spoon.
Turn off the heat and let it cool. Make puree.
Again in the same pan, put some oil and once it is hot add the whole spices: Cloves and Green Cardamom. Now add the puree, mix everything and add the turmeric & red chilli powder. Mix again.
Also, now add the dried oregano and ketchup. Crush some kasoori methi between both hands and add it to the pan.
Put in the coriander-cumin powder now. Keep cooking for few minutes and adjust the consistency.
Let the sauce cool completely before using on pizza dough.