This roasted tomato soup transforms simple farmers market tomatoes into a deeply flavorful, silky-smooth comfort meal. Roasting the tomatoes at high heat caramelizes their natural sugars, creating layers of sweetness and depth that no canned soup can replicate. Finished with heavy cream and fresh basil, it's a restaurant-quality bowl you can make on any weeknight.
Preheat your oven to 425°F (220°C) and line a large rimmed baking sheet with parchment paper. Halve the Roma tomatoes lengthwise and arrange them cut-side up on the pan along with the quartered onion and peeled garlic cloves.
Drizzle everything with olive oil and sprinkle with salt, black pepper, and red pepper flakes (if using). Roast for 40–45 minutes until the tomatoes are slightly charred at the edges and the onions are soft and caramelized, rotating the pan halfway through.
Let the baking sheet cool for 5 minutes, then scrape all the roasted vegetables — including any caramelized bits and pan juices — into a large pot or Dutch oven.
Pour in the broth, add the basil and thyme, and bring to a boil over medium-high heat. Reduce to medium-low and simmer for 10 minutes to meld the flavors.
Remove from heat and cool slightly for 3–4 minutes, then blend with an immersion blender (or in batches in a regular blender) for 1–2 minutes until completely silky and smooth.
Return the pot to medium-low heat, stir in the heavy cream and balsamic vinegar, and heat through for 2–3 minutes without boiling. Taste and adjust salt and pepper as needed.
Ladle the soup into bowls and garnish with torn fresh basil, a drizzle of olive oil, or a dollop of sour cream. Serve immediately with crusty bread or grilled cheese.
Notes
Use ripe tomatoes for the best flavor — underripe tomatoes will make the soup taste flat and acidic.
Don't crowd the baking sheet or vegetables will steam instead of roast; use two pans if needed.
Roast until you see char on the tomato edges — that caramelization is essential for deep flavor.
Add cream at room temperature and never boil the soup after adding it to prevent curdling.
If the soup tastes too acidic, balance it with a pinch of sugar or an extra splash of balsamic vinegar.
For a dairy-free version, substitute full-fat coconut milk or cashew cream for the heavy cream.
Refrigerate leftovers in an airtight glass container for up to 5 days — the flavor deepens overnight.
To freeze, leave out the cream and freeze for up to 3 months; stir in cream when reheating.
Outside of tomato season, substitute two 28-oz cans of San Marzano whole peeled tomatoes, drained.
For a spicier version, blend in 1–2 chipotle peppers in adobo sauce before adding the cream.