In a large stockpot heat oil over medium heat. Add the onions and carrots and sauté until tender. Add the garlic, cook for 30-40 seconds, stirring so the garlic doesn't burn.
Still over medium heat, add the chopped tomatoes, tomato paste, basil, sprig of thyme, bay leaf, sugar, salt, and pepper, stir well. Increase heat to medium high and add the chicken stock, stir and bring to a boil. Now reduce heat to low, simmer uncovered for 45 minutes.
Remove bay leaf and sprig of thyme, discard.
IMMERSION BLENDER: Turn heat off and use an immersion blender to purée soup right in the stockpot. Once complete, turn heat to medium-low, add heavy cream, stirring until incorporated and heated throughout. Adjust salt and pepper to taste. Enjoy!
REGULAR BLENDER: Turn heat off. Allow soup to cool before placing (in small batches or as much as you safely can) into a blender, cover with a hand towel, and purée until smooth. Repeat until all the soup is puréed; ladle soup back into the stockpot. Turn heat to medium-low, add heavy cream, stirring until incorporated and heated throughout. Adjust salt and pepper to taste. Enjoy!
OPTIONAL STEP: Pour puréed soup through a fine mesh strainer into a bowl, then return back to stock pot. If you don’t have time or want to strain the soup, don’t worry just skip this step.