Heat 3 tablespoons of butter 2 tablespoons of oil together in the inner pot of Instant pot or traditional pressure cooker.
Add garlic paste, green chili paste, 1 cup of sliced or chopped capsicum and sauté for 30 seconds.
Add chopped onions and sauté for 1 minute or until onions are soft and pink.
Add chopped beetroot, tomatoes, Kashmiri red chilli powder and 2 tablespoons of pav bhaji masala powder. Sauté for another minute.
Add potatoes, cauliflower and green peas, mix. Add 1.5 cups of water and salt to the pot and stir once.
Close the pot with valve in sealing position, cancel sauté button and press manual/pressure cook button. Pressure cook the veggies for 8 minutes on high pressure. In a traditional pressure cooker, cook for 2-3 whistles on high flame and then simmer for 6-7 minutes on low heat.
Once cooking is over, let the pressure release naturally.
Carefully open the lid, and with the help of masher or immersion blender, smash the bhaji.
Switch on the sauté mode again in Instant Pot. (Switch on the heat of stove top for traditional pressure cooker method).
Add kasuri methi, remaining butter and of pav bhaji masala, and check for the salt. If you feel bhaji is too thick, then add little water and allow it to simmer for 2-3 minutes.