Preheat the oven to 400°F (200°C).

On a sheet pan, toss the carrots, celery, onion, bell peppers, and garlic with olive oil, salt, and pepper.

Spread the vegetables evenly on the sheet pan and roast in the preheated oven for 25-30 minutes, or until tender and slightly caramelized.

In a large pot, combine the roasted vegetables with vegetable broth, thyme, and oregano.

Bring to a boil, then reduce heat and simmer for 10-15 minutes.

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

Adjust seasoning with additional salt and pepper if needed.

Ladle the soup into bowls and serve hot.