Add the 2 tablespoons oil or butter to a large stock pot or soup pot and turn heat to medium
Once oil is hot, add the onions and saute for 3-4 minutes until slightly translucent, then add the minced garlic and cook for another 4-5 minutes until fragrant
Add the onion and garlic mixture to a blender with all three cans of tomato product and blend until smooth.
Add the mixture back to the stock pot and return heat to medium high
Add all the remaining ingredients (except the extra pesto and olive oil to be reserved for serving)
Bring the soup to a light boil. Once the soup comes to a light boil, reduce heat to low and simmer for about 15-20 minutes.
In a small bowl, mix the reserved 2 tablespoons of pesto with about 2 tablespoons olive oil and whisk until it becomes a smooth consistency.
Serve the soup in bowls and add a spoonful of the pesto mixture in a swirl pattern.