Turn the Instant Pot on “Sauté” and wait for it to heat up.
Add the oil and butter and once hot, add the onion and garlic and cook 2 minutes, stirring regularly. Press “Cancel” to turn off the Instant Pot.
Stir in the crushed tomatoes, tomato paste, dried Italian herb seasoning, salt, sugar, black pepper, and chicken stock. Put the lid on the Instant Pot and set it to “Sealing”.
Cook on “Manual, High Pressure” for 5 minutes. Once it’s finished, carefully release the valve.
If you want a smooth and creamy soup, carefully puree the soup with an immersion blender or transfer it to a regular blender and process until smooth.
Stir in the heavy whipping cream.
If desired, serve the soup with more cream drizzled on top, along with fresh basil.