Heat one tablespoon butter in a pan and add the cumin seeds.
When cumin seeds start to crackle add onions, chopped tomatoes and capsicum, and water.
Cook on a medium flame for 5-7 minute, stir it in between and cook till slightly mushy.
Add the tomatoes, salt, chili powder, pav bhaji masala and 1 cup of water.
Mix everything together and cook few more minutes, while stirring and mashing it occasionally.
Finally, remove it from heat and add the coriander and chopped green chilli.
FOR SERVING
Heat 1 teaspoon of butter on tava (griddle), add a portion of the prepared aloo masala add 3-4 tablespoon of water and cook for few seconds.
Slit 1 pav horizontally, let it stay attached from one side.
Spread the masala evenly over the pav till it gets evenly coated from all the sides.
Serve hot.