01 - Heat olive oil in a large pot over medium heat. Add diced onion and carrot, sautéing for 5 minutes until softened and translucent.
02 - Stir in minced garlic and cook for 1 minute until fragrant, being careful not to brown it.
03 - Add diced tomatoes with their juices, fresh basil, vegetable broth, sugar, salt, black pepper, and crushed red pepper flakes. Stir well to incorporate all flavors.
04 - Bring mixture to a simmer, then reduce heat to low. Cook uncovered for 20 minutes, stirring occasionally to develop flavor.
05 - Remove from heat. Using an immersion blender, puree soup until completely smooth. Alternatively, carefully blend in batches using a standard blender.
06 - Stir heavy cream into the pureed soup. Reheat gently over low heat for 2–3 minutes, being careful not to boil. Taste and adjust salt and pepper as needed.
07 - Ladle hot bisque into serving bowls. Garnish with additional fresh basil leaves and serve immediately while hot.