Turn Instant Pot to the sauté setting. When "HOT" add olive oil. Add onion and stir for about 3 minutes. Stir in garlic and sauté another 30 seconds. Turn off sauté setting.
Add in chicken, canned beans, chicken broth, spices and green chilies. Mix together.
Cover Instant Pot and secure lid. Set valve to sealing. Set the manual button or pressure cook button to 20 minutes. Or 25 minutes if the chicken is frozen.
When the timer beeps, leave lid on for another 10 minutes. Move the valve to venting to release any remaining pressure.
Remove the chicken and shred. Return to pot.
In a small saucepan melt the butter and whisk in the flour until smooth.
Turn the Insta Pot to "Saute" and stir butter mixture into the soup. Allow to cook for 5 minutes until soup thickens, stirring every minute or so.
Stir in milk, sour cream, lime juice and chopped cilantro. Salt and pepper to taste.
Serve with cheese, cilantro, avocado and corn chips!