Set the pressure cooker to Saute mode and heat oil for a few seconds. Once the oil is warm, add in the cumin seeds.
As soon as the cumin seeds start to sizzle, add in the ginger, garlic, chopped onion and green pepper, and fry for a few minutes till begin to lightly brown along the edges.
Add in the tomato paste and spices, and fry for a few seconds to mix everything well.
Add in chopped tomatoes, give it a food mix and let it cook for a few minutes till the tomatoes start to pulp and blend with the spice mixture. Keep stirring occasionally to prevent the bottom from getting burnt.
Mix in the potatoes, carrots, peas and corn, and add in the water. Give it another mix and close the lid of the pressure cooker. Set it to the Pressure cooking mode with the timer set to 5 minutes.
Once the time is done, allow the pressure to release naturally. Be careful while opening the lid, and give it a good stir. Using a potato masher, carefully mash the curry into a smooth consistency. You can add in more hot water depending on how thick you like your Bhaji. Adjust the seasoning and add in salt if needed.