Wash and chop the veggies. Take them into pressure cooker. Add salt and water.
Cover with the lid, put the weight on and turn the heat on medium.
Let it whistle for 2-3 times. Then turn off the stove
Let the pressure go down by itself and open the lid.
Instead of pressure cooker you can cook in a pot on stove top as well. Cook till vegetables are soft and tender, you may need more water or vegetable stock for cooking.
Now using immersion blender, start making the puree.
You can use blender as well. Blend it till it gets smooth and pureed.
Add black pepper powder.
Put it back on the medium heat and bring it to a boil. You can adjust the consistency as per your liking by adding more water or stock.