Press Manual, HIGH pressure, and select 4 minutes.
Let the pressure release naturally.
Once the pin drops down, open the lid and let the mixture cool.
After it has cooled completely, blend it in a blender until smooth. You can do it in batches.
Adjust the consistency of the soup by adding more stock or water if desired. You can taste and adjust the seasoning as well.
You can return the soup to the pot to simmer until warm just before serving.
Add some black pepper and croutons on the top if preferred so.
Video
Notes
You can skip celery if unavailable. Add chopped onion instead.Skip oil to make it oil-free.The soup thickens considerably after cooling or if there are any leftovers.You can add some water and adjust the consistency.Swap vegetable stock for water and 1 tablespoon "better than bullion" or tastemaker of choice.Leftover stays good in the fridge for up to 3 days and freezer for 2 months.