01 -
Heat the olive oil in a large pot over medium heat. Add the chopped onion and sauté until softened, about 5 minutes. Stir in the minced garlic and cook for another minute.
02 -
Add the diced tomatoes, vegetable broth, sugar, salt, and black pepper. Bring the mixture to a simmer and cook for about 15-20 minutes, letting the flavors meld.
03 -
Use an immersion blender to puree the soup until smooth, or carefully transfer it to a blender in batches. Return the soup to the pot.
04 -
Stir in the chopped basil and balsamic vinegar. Taste and adjust seasoning if needed. Heat through for a couple of minutes.
05 -
Serve hot, garnished with fresh basil leaves.