Heat Butter in a thick bottom pan or Tawa.
Add chopped Onion, grated ginger and chopped green chilli in the pan and saute on medium heat for 2-3 minutes.
Add chopped capsicum and suate for 2-3minutes.
Add Tomatoes and salt cook for 4-5 minutes and mash with a potato masher.
Add red chilli powder, coriander powder, pao bhaji masala and saute for few minutes, till baby corn becomes tender. Add 2-3 tablespoon of water in between as and when required to keep the masala wet.
Add chopped and cleaned mushrooms and cook for 4-5 minutes over high heat while stirring them all the time.
Serve it hot and garnish with fresh coriander leaves and lemon juice.