Grind the ginger and garlic into a fine paste.
Heat the butter in a pan and sauté the degi mirch and onions.
When the onions turn soft, add the green chillies and ginger-garlic paste.
Stir-fry for half a minute and add half of the tomatoes. Cook the tomatoes for 3- minutes on a medium flame, stirring constantly till the oil separates from the masala.
Add the capsicum, cauliflower, mashed potatoes and 1½ cups of water. Boil the bhaji for 10 minutes and roughly mash the vegetables with a back of a spoon.
Add Kohinoor Mumbai Pav Bhaji Masala, salt and the remaining tomatoes.
Cook on a medium flame for 2 minutes, stirring constantly. Season with salt as required.
Heat 2 tbsp. butter in a thick-bottomed tawa or pan.
Slice the pav horizontally and roast it on the pan for half a minute, pressing down on it 2- times till the pav is crisp and light brown.
Garnish the bhaji with fresh coriander, the remaining butter and serve with the hot pav, chopped onion and lemon wedges.