This might just be the carrot soup you've been looking for...the one with bacon and garlic? I don't peel the carrots and potatoes but you do have to wash them well...so you might find it easier to peel.
Peel the onion. Wash or peel the other vegetables. Remove the ends of carrots and celery. Cut vegetables into large pieces.
Place all ingredients in the pressure cooker and after it comes to pressure, cook for 20 to 25 minutes.
Once cooked, carefully release the lid and blend the soup in a blender or with a stick blender. Add extra water to get it to your desired consistency. Adjust seasoning and serve hot, with a little cream and bread.