Turn the Instant Pot to the Saute-Normal function. Heat the olive oil and butter for 1-2 minutes, or until the butter has melted.
Add the onion and cook until it is soft and starting to turn golden brown around the edges— about 5 minutes.
Next, add the garlic and sage. Cook for an additional minute.
Add the thyme, butternut squash, vegetable stock, and salt. Attach the lid and ensure the valve is in the “sealing” position.
Note: I like to tie all of the thyme stems together using butcher’s twine. It makes it easier to get out once the soup has finished cooking.
Cook the soup on the Manual Pressure- High Pressure- Normal setting for 12 minutes.
Note: The Instant Pot will display “on” while it is pressurizing. Once at pressure, it will begin counting down from 12.
Once the Instant Pot has finished cooking, release the steam manually by switching the valve from the “sealing” position to the “venting” position.
Note: Be careful! It will release steam and may splatter. I like to move the valve with a long kitchen spoon or tongs— not my bare hand!
Remove the thyme stems. Use an immersion blender to blend the soup until smooth.
Note: If you don’t have an immersion blender, you can transfer the soup to a regular blender or food processor.
Add the heavy cream and stir to combine.
Serve hot, topped with goat cheese, freshly cracked black pepper, and fresh sage or thyme, if desired.
This soup can be made in advance and kept warm using the “keep warm” function on the Instant Pot for up to one hour.
Butternut squash soup should be kept in an airtight container in the refrigerator for up to 4 days. Reheat in the microwave or on the stovetop over low heat. If the soup thickens, thin it with milk.