Turn on the Sauté feature of your pressure cooker (med/normal heat). Add the bacon and cook until done. Transfer to a paper towel and discard all but 2 tsps of the fat.

Add the butter, onion, and bay leaf to the pot and cook, stirring and scraping the bottom of the pot, until the onion turns translucent. You might need to splash in a little bit of broth to help get all of the brown bits off the bottom of the pot (deglaze).

Add the garlic, salt, and pepper. Cook for 1 minute, or less if it gets fragrant, stirring constantly. Don't let the garlic burn.

Stir in the chicken broth.

Add the cauliflower and ⅔ of the reserved bacon (saving ⅓ for garnish). Stir.

Place the lid on the pot and lock in place. Set the steam release knob to the Sealing position.

Cancel the Sauté function.

Press the Pressure Cook (or Manual) button, or use dial, and then the + or - to choose 4 minutes. When cooking cycle finishes, let the pot sit and enter the Natural Release (Keep Warm) phase for 10 minutes.

Turn the steam release knob to the Venting position to release the remaining pressure from the pot (on the Ultra, push the button). When the pin in the lid drops down, open the lid and stir the soup.

Remove the bay leaf.

Stir in the arrowroot slurry.

Use an immersion blender to puree the soup. If you don't have one, use a potato masher to mash up the cauliflower pieces.

Stir in the heavy cream.

Taste and adjust salt, if needed.

Serve hot, garnished with the reserved bacon.