Add vegetable oil and butter to a large tawa or heavy bottomed pan and allow to heat on a medium high flame. Once hot, add cumin seeds and let it splutter. Add capsicum and saute for 5 minutes on medium flame or until slightly softened.
Add chopped onion and allow to fry on medium flame for 6-7 minutes. Add chopped tomatoes, 2 teaspoons pav bhaji masala and 1 teaspoon of salt. Stir to combine, cover and cook on low heat for 8-10 minutes or until softened.
Add chilli powder, coriander powder, turmeric powder, 2 teaspoons of pav bhaji masala, 1 ½ tablespoons of garlic paste, green chilli paste and ½ a teaspoon of salt. Stir and mix until combined. Cook on medium heat for 3-4 minutes or until the oil separates.
Add mashed potato, carrots, beetroot and green peas. Stir to combine. Add 1 cup of water and mix well. Allow it to come to a boil and mash using a potato masher. Allow the bhaji to reduce and cook on a medium flame.
Once the water gets absorbed, add another cup of water along with half a teaspoon of salt and repeat the mashing process. Ensure all the vegetables are fully cooked and mashed together.
Taste and adjust the salt accordingly. You can add another cup of water if you like a more runny consistency, I used a total of 3 cups of water.
Add butter, kasuri methi, ½ a tablespoon of garlic paste and ¼ cup of chopped coriander leaves and stir to combine. Simmer it for 1-2 minutes or until butter has melted through. Once it melts, add lemon juice and the remaining coriander leaves, stir to combine. Serve hot along with chopped onion, lemon wedges and hot toasted pav!