Step 1: Roast Tomatoes and Garlic : Preheat oven to 400°F (200°C). Place halved tomatoes and unpeeled garlic cloves on a baking sheet. Drizzle with olive oil and sprinkle with salt, pepper, thyme, and oregano. Roast for 25–30 minutes until tomatoes are soft and slightly caramelized. Allow garlic to cool slightly, then squeeze out roasted garlic cloves.
Step 2: Sauté Onion : In a large pot, heat 1 tbsp olive oil over medium heat. Add chopped onion and sauté for 3–4 minutes until translucent.
Step 3: Combine and Simmer : Add roasted tomatoes, roasted garlic, and broth to the pot. Bring to a gentle simmer and cook for 10 minutes to meld flavors. Stir in sugar (if using) and adjust salt and pepper.
Step 4: Blend the Soup : Use an immersion blender to puree the soup until smooth. Alternatively, carefully transfer to a blender in batches. Stir in heavy cream and chopped basil. Reheat gently if needed, but do not boil once cream is added.
Step 5: Serve : Ladle soup into bowls. Garnish with fresh basil, croutons, or a drizzle of cream. Serve hot with toasted bread or a grilled cheese sandwich.