Chop the veggies, coriander leaves and keep it aside.
Take a pressure cooker and add oil to the cooker. Then add pav Bhaji masala to the cooker. Then add veggies like potato, carrot, green peas to the cooker.
Slightly fry the veggies in the masala and add water and cover the lid. Pressure cook the veggies for 2 whistles or else until they properly cooked.
At this stage can add the veggies of your choice like cauliflower, beetroot.
Preparation for Bhaji:
Take a wide pan or Kadai and add the oil and butter to the pan. When the butter is melted add chopped onions to the pan.
When they are lightly fried add ginger garlic paste. Saute it until the raw flavor is gone.
Then add finely chopped capsicum to the pan. when the capsicum is slightly cooked add chopped tomato.
Cook the tomatoes until they become soft. Then add salt, chili powder, green chilis, pav bhaji masala and mix well.
Fry the spices along with the veggies. Then add boiled veggies to the pan and mix well with the spices in the pan. Add some water if required. Then add chopped coriander leaves and mix well.
Then mash the veggies with the potato masher or spatula. Don't paste the veggies, you should have chunks of veggies in the Bhaji.
After that add the lemon juice to the pan and mix well. When Bhaji is thick enough turn of the stove.
Preparation of Pav:
Heat the pan and add some butter on the pan. When the butter is melted sprinkle some Pav Bhaji masala on the pan.
Then keep the pav on the pan and apply some more butter on the top of the pav. When the pav is roasted on one side turn it to the other side.
Repeat the procedure for the other pav also . Can add Bhaji on the Pan, to roast the pav for extra flavor.
Now serve the pav with the bhaji with extra butter on the top, along with the chopped onions and lemon slice.