Add potatoes, broth, onion, and seasonings to the instant pot.
Set to 5 min at HP (high pressure).
Once the soup has cooked and the timer goes off, do a QR (quick release) and remove the lid.
Using an immersion blender, blend the soup for 10 seconds or so, just until most of the potatoes are broken up and you’re left with very small chunks. You can blend it as little or as much as you like.
Combine arrowroot and water to make a thickening slurry.
Add slurry to the soup and stir until it has thickened. If you do this immediately after doing the QR (it should still be on the “keep warm” setting), your soup will be hot enough for it to thicken. If it isn’t, just turn it to the saute mode and allow it to heat up that way.
Finally mix in butter and sour cream to the final mixture and stir to combine.
Simple comfort food is my favorite! Enjoy!
Recipe Notes
For the stovetop version:
In a large pot, saute onions in 1 tbsp of oil over medium heat for 3-5 minutes until softened.
Add potatoes and cook for another 5 minutes.
Add broth and seasonings and bring to a boil.
Cover, reduce heat, and cook until the potatoes are soft and fork tender.
Add arrowroot slurry to soup and stir until thickened.