Turn Instant Pot to saute and add butter and a drizzle of oil.
Add onion, broccoli and garlic to soften. Stir.
Add in cream cheese, cheddar cheese and heavy cream. Stir
Add in broth and stir.
Put lid on pressure cooker and set to soup setting for 20 minutes.
Wait for the beep. Release the pressure carefully.
Stir Soup. If you want it thick take out a little soup in a bowl and mix in the arrowroot powder. Mix until it's not lumpy. Add mixture back into the pot. Stir until thickened. Add more if needed.
Serve with extra cheese, bacon or green onions on top.