Roasting the tomatoes concentrates their sweetness and adds a smoky depth that canned tomatoes just can't match. This soup is best paired with a grilled cheese sandwich.
- Preheat oven to 400°F (200°C). Halve the tomatoes and arrange them on a baking sheet along with the whole garlic cloves (peeled) and onion wedges. Drizzle generously with olive oil, salt, and pepper.
- Roast for 40-45 minutes until the vegetables are soft and charred at the edges.
- Transfer the roasted vegetables and their juices to a blender or large pot. Add the fresh basil and vegetable broth. Blend until smooth (or leave chunky if preferred).
- If blending, return the soup to the pot. Stir in the heavy cream and simmer for 5 minutes. Adjust seasoning with more salt or a pinch of sugar if the tomatoes are acidic.