Roughly cut the potatoes in halves or thirds, so that all the pieces are about the same size. Add the peeled potatoes, garlic, leeks, stock and water to the pressure cooker. Close and lock the lid, then set to cook on High Pressure for 10 minutes.
Fry the bacon crispy, and let the bacon drain on a paper towel-lined plate. When the bacon is cool enough to handle, chop it finely and set aside.
After the pressure cooker’s time is up, let the potatoes finish cooking with a natural release. Remove the lid and add the milk and cream cheese.
Blend the potato soup until smooth. This can be accomplished right in the pressure cooker pot with an immersion blender, or you can transfer the contents of the pot to a blender or food processor and blend til smooth., working in batches if necessary. Remember, if you are using a blender or food processor, to cover the lid opening with a towel in order to allow steam to escape as you blend. Season the soup to taste with salt and pepper.
To serve, ladle the blended soup into bowls and top with bacon and green onions.