Preheat the oven to 400°F (200°C).

On a baking sheet, toss the halved tomatoes, chopped onion, minced garlic, carrots, and celery with olive oil, salt, and pepper.

Spread the vegetables in a single layer and roast for 30-35 minutes until caramelized.

Transfer the roasted vegetables to a large pot.

Add the vegetable broth and bring to a simmer over medium heat.

Stir in the fresh basil and dried oregano.

Use an immersion blender or transfer to a blender to puree the soup until smooth.

Taste and adjust seasoning with more salt and pepper if needed.

Serve hot, garnished with additional basil leaves if desired.