Saute Onion and Garlic:

In a large Dutch oven, combine olive oil and butter. Heat over medium heat until the butter is melted.

Add the chopped onion. Cook, stirring frequently, until softened, about 8 minutes.

Stir in the minced garlic and cook for another 5 minutes or until very fragrant and just starting to brown.

Add Tomatoes and Stock:

Add the whole peeled tomatoes to the pot. Swirl the cans with some of the chicken stock to get the rest of the tomato juices and pour into the pot with the remaining stock.

Stir in the granulated sugar and black pepper. Bring to a boil, about 10 minutes.

Reduce the heat to medium-low and continue simmering for 30 minutes, stirring occasionally.

Blend and Season:

Remove from the heat. Using an immersion blender, pulse the soup to break up the tomatoes a bit or until your desired consistency. (Avoid using a high-speed blender as blending olive oil can turn it bitter. Alternatively, mash with a potato masher to break up the tomatoes.)

Taste and add salt, if needed.

Finish and Serve:

Stir in the heavy cream. Serve immediately topped with fresh chopped basil.

Enjoy your delicious homemade tomato soup!