Wash, peel and roughly chop all the vegetables.
Add the vegetables to a pressure cooker with a glass of water and salt to taste. Cook for up to 4 whistles.
When the pressure is gone, let it cool before grinding to a puree.
In a kadhai or wok, melt butter, and saute ginger.
Add onions and saute till dark brown. Add tomatoes and cook till the oil separates.
Mash the boiled peas slightly before adding to the pan. Follow with all the masala powders.
Now add the vegetable puree and mix well. Let it simmer on a low flame for 15-20 minutes. Squeeze lemon juice over the bhaji.