Add the peeled and chopped vegetables into a pressure cooker. Add 1.5 cups water, cover and cook for 2 whistles. Allow to cool and depressurize naturally. Remove the top and mash the vegetables and water.
Prepare the Pav Bhaji stew
Heat 1 tablespoon of butter and 1 tablespoon of ghee in a kadai pan. Add the finely chopped onions and stir fry for several minutes until soft and transluscent. Add the green chili, garlic and ginger. Stir and cook for several more minutes.
Add the chopped tomatoes, Kashmiri chilli powder, turmeric, pav bhaji masala and salt. Cook and stir untill the tomatoes are soft and mushy.
Add the mashed vegetables. Stir and cook until thick. Remove from heat and mix in the crushed kasuri methi. Set aside and prepare the pav rolls.
Prepare the Rolls
Split the rolls in half. Butter each half and sprinkle with a little bit of pav bhaji masala. Grill each roll on the buttered side. Serve with the pav bhaji stew and lemon wedges, chopped onion and chopped cilantro.