Preheat oven to 400°F (200°C). Place tomatoes and garlic cloves on a baking sheet. Drizzle with 2 tablespoons olive oil, season with salt and pepper, and roast for 25 minutes, or until soft and charred.

While tomatoes are roasting, heat 1 tablespoon olive oil in a large pot over medium heat. Add onion and potato; cook until onion is translucent and potato begins to soften, about 6-7 minutes.

Stir in the roasted tomatoes, garlic, and vegetable broth. Bring to a boil, then reduce heat and simmer for 15 minutes, or until potato is tender.

Add fresh basil and simmer for 2 minutes. Blend soup with an immersion blender until smooth.

Optional: Strain soup through a fine-mesh sieve for an even smoother texture.

Serve hot with a drizzle of olive oil and a sprinkle of fresh basil.