Turn on the "Saute" mode in the instant pot.
When the pot is hot, add butter and oil.
Once butter is melted, add onion, celery, garlic and saute for a few minutes until onions are partially softened and garlic is fragrant.
Add broth, cream of chicken soup, potatoes, bay leaf, dried oregano, dried thyme, salt, pepper and mix until combined.
Put the lid on and turn the valve to “Sealing.”
Select “Manual” mode and set the timer for 10 minutes.
When the cook time is over, do a quick pressure release.
In a small bowl, mix together milk and flour until you have a smooth slurry
Remove lid and pour slurry, while mixing.
Continue cooking on the "Saute" mode to reduce excess liquid and thicken the soup to your desired consistency.
Discard bay leaf.
Use a hand-held immersion blender to puree mixture until smooth.
Stir in shredded cheese and stir until melted.
Garnish with bacon bits and additional cheese. Enjoy.