Finely chop onion, carrots (optional), tomatoes, capsicum (chop the vegetables as finely as you can).

Heat oil in a pan, add cumin seeds, after 1 sec add ginger/garlic taste. Saute for few seconds then add chopped onions and saute till they are brown, next add carrots and capsicum and saute them for couple of mins.

Once the added veggies are little tender, add tomatoes and give it a stir and then add the pav bhaji masala, chilli powder and salt to taste. Let the mixture cook completely.

Now set aside the cooked mixture, let it cool slightly. Then mash the mixture little bit.

Now take the pav, slit it from the center, pat some butter in the inner part of the pav and then add the cooked mixture inside. Close the pav and place it on a skillet add butter and fry it from both sides so that the pav is bit crispy (I like it this way). You can even keep it soft if you like it that way.