Heat olive oil in a saucepan over medium heat. Add chopped onion and sauté until translucent, about 5 minutes.

Add minced garlic and cook for an additional minute until fragrant.

Stir in the chopped tomatoes and vegetable broth. Bring to a boil, then reduce heat and simmer for 20 minutes.

Add fresh basil leaves, salt, and pepper. Remove from heat.

Using a blender, puree the soup until smooth. Return to the saucepan and heat through if necessary.