Creating this incredible Roasted Tomato Soup is straightforward. Follow these simple steps:

1. Preheat Oven: Preheat your oven to 400°F (200°C).
2. Prepare Tomatoes: Place the halved tomatoes on a baking sheet, cut side up.
3. Add Vegetables: Scatter the diced onion and minced garlic around the tomatoes.
4. Season: Drizzle with olive oil, then sprinkle with salt, pepper, and dried basil. Toss gently to coat.
5. Roast: Roast in the preheated oven for 30-40 minutes until the tomatoes are caramelized.
6. Combine: Transfer the roasted tomatoes, onion, and garlic to a large pot. Add the vegetable broth and sugar (if using).
7. Blend: Use an immersion blender to puree the soup until smooth. Alternatively, transfer in batches to a countertop blender.
8. Adjust Seasoning: Stir in balsamic vinegar if desired, and adjust seasoning to taste.
9. Heat: Return the soup to the stove and heat gently over low heat until warmed through.

These steps will guide you in creating this amazing soup effortlessly.