Set instant pot to Sauté mode. Once heated, add 1 ½ tbsp of olive oil to pot. Add mushrooms and sauté for 5-8 minutes until soft and water from mushrooms has been released. Remove mushrooms and juices into a separate bowl and set aside.
While the instant pot is still on sauté mode, add remaining 1 ½ tbsp of olive oil into the pot. Once oil is hot, add yellow onion and cook for 3-5 minutes, stirring often. When onions are translucent, add cauliflower and sauté for an additional 2 minutes.
Turn the instant pot off and add broth, thyme, chicken and juice from mushrooms (not the actual mushrooms) to the onions and cauliflower. Seal the lid, and pressure cook for 20 minutes. When time is up, quick-release the pressure, being careful not to burn yourself.
Once pressure is released, remove chicken and shred.
Use an immersion blender to blend the contents left in the instant pot. Adding one tablespoon at a time, add arrowroot and continue to blend the mixture until all the arrowroot is added. Once blended thoroughly, the soup should have thickened.
Add the chicken and mushrooms back into the instant pot and stir. Add the coconut milk into the pot and stir to combine. Season with salt and pepper to taste.
Serve warm, top with chives or green onion and enjoy!
