Step 1Turn on the pot's sauté function and add the chopped bacon and onion. Cook until bacon is done and onions are translucent, stirring occasionally.Add the celery. Stir, and scrape up any brown bits from the bottom of the pot (deglaze).Add the potatoes, broth, salt, and pepper. Put the lid on and lock in place. Set the steam release knob to the Sealing position, if applicable.Cancel the sauté setting and push the Pressure Cook/Manual button, or dial. Use the + or - button, or dial to select 8 minutes.When the cook cycle ends, let the pot sit undisturbed for 10 minutes (10 minute natural release). Then do a controlled quick release of the remaining steam/pressure (release steam in short bursts until you are sure no soup will spew out with the steam).While the pot is naturally releasing, combine the softened butter and flour in a small dish, using a fork. If the butter isn't soft enough, warm it in the microwave for 10 seconds. Mix thoroughly until all lumps are gone.When all of the pressure is out of the pot, carefully open the lid, and turn on the sauté setting. Let the soup come to a simmer (don't let the soup scorch on the bottom), then stir in the flour mixture and stir until thickened.You can use a potato masher to mash some of the potatoes to help it thicken a little more and give the soup more texture.Cancel the sauté setting and stir well. Then Add the heavy cream. Taste and adjust salt if desired.Serve with some crusty bread.