Creating Roasted Tomato Basil Soup can be straightforward if you follow these simple steps:

1. Preheat your oven to 400°F (200°C).
2. Prepare the Vegetables: Cut the tomatoes in half and place them on a large baking sheet. Scatter the chopped onion and whole garlic cloves around the tomatoes.
3. Add Olive Oil: Drizzle the vegetables with olive oil, then sprinkle with salt, pepper, and sugar if using. Toss gently to coat.
4. Roast: Place the baking sheet in the preheated oven and roast for 25-30 minutes, or until the tomatoes are soft and caramelized.
5. Blend the Soup: Remove the veggies from the oven and let them cool slightly. Transfer them to a blender. Add the broth and fresh basil leaves, then blend until smooth.
6. Adjust Consistency: If the soup is too thick, add a bit more broth or cream to reach your desired consistency.
7. Heat the Soup: Pour the blended soup into a saucepan and heat over medium heat. Taste and adjust the seasoning with salt and pepper.
8. Add Cream: For a creamier texture, stir in heavy cream or coconut milk. Heat until just warmed through.
9. Serve: Ladle the soup into bowls and garnish with fresh basil leaves.

Each step is designed to guide you effortlessly in creating this fantastic soup.