Homemade Tomato Basil Soup made from oven-roasted tomatoes, fresh garlic, gently caramelized onions, and bright basil. This version balances fresh, vibrant tomato flavor with a comforting, smooth texture. It’s simple to prepare year-round using either fresh or canned tomatoes, and it’s naturally vegetarian and gluten-free unless you choose garnishes that add dairy.
Roasted Tomato Basil Soup
There are many takes on tomato soup: some are rich and creamy, others are bright and roasted. This recipe leans toward the latter—fresh-tasting and layered with sweetness from roasted tomatoes and depth from caramelized onions. The result is a silky, satisfying soup that still lets the tomato shine.
I like to combine fresh, oven-roasted tomatoes with high-quality canned tomatoes for the best flavor with minimal effort. Olive oil, garlic, onions, basil, and a little broth round out the soup. You control the texture—blend until just smooth for body, or a little longer for an ultra-silky finish.
What types of tomatoes should I use?
Any tomato works: fresh or canned, Roma/plum, San Marzano, fire-roasted, or cherry tomatoes. For the most balanced flavor, use a mix of roasted fresh tomatoes and canned whole or crushed tomatoes. If using only fresh tomatoes, you’ll need more—see the notes in the recipe section below.
How to Make Tomato Basil Soup
1. Roast the tomatoes and garlic: Preheat the oven to 425°F (220°C). Roast halved Roma or plum tomatoes for about 40–45 minutes; roast cherry tomatoes 18–25 minutes. Add whole garlic cloves to the tray so they soften and sweeten as they roast.
2. Caramelize the onions: In a large pot or Dutch oven, heat a little olive oil and butter (or a dairy-free alternative). Cook sliced onions over medium heat for at least 15 minutes, stirring occasionally. Longer cooking (20–30 minutes) develops more sweetness and depth.
3. Combine ingredients: Add the canned tomatoes (with their juices), fresh basil leaves, broth, a teaspoon of sugar if desired, and red chili flakes. Bring to a simmer. When the roasted tomatoes are ready, add them with any pan juices and simmer gently for another 10–20 minutes to meld flavors.
4. Blend: Carefully puree the soup in batches in a blender or use an immersion blender. Blend until smooth but avoid overworking it—excessive blending can thin the texture too much. Return the soup to the pot and adjust seasoning with salt and pepper.
5. Finish and serve: Serve hot, garnished with torn basil leaves, a drizzle of cream or coconut milk if you like it creamy, and crunchy croutons or crackers on the side.
How to make it creamy
After blending, whisk a small amount of tomato paste with a ladle of hot soup, then stir in your preferred cream (heavy cream or coconut milk) and mix back into the pot over low heat. Heat gently until warmed through—do not boil once cream has been added.
Frequently Asked Questions
No, roasting is optional. Roasting concentrates sweetness and adds caramelized flavor, but you can skip it and use only canned tomatoes or peeled, blanched fresh tomatoes for a quicker method.
Cook onions for at least 15 minutes. For a richer, sweeter base, aim for 25–30 minutes over moderate heat, stirring frequently to avoid burning.
A small amount of sugar helps balance tomato acidity and round out flavor without making the soup noticeably sweet. One teaspoon is usually enough.
Yes. If you skip canned tomatoes, increase fresh tomatoes—approximately double the fresh quantity recommended in the recipe—so the soup remains flavorful and balanced.
Stored in an airtight container, the soup keeps in the refrigerator for 4–5 days. Reheat gently on the stovetop or in the microwave.
How to Serve
The classic pairing is a buttery grilled cheese sandwich. If you prefer something lighter, serve with crusty bread, garlic-toasted baguette slices, or crackers. Garnish ideas: torn fresh basil, a swirl of cream or coconut milk, a pinch of red pepper flakes, or freshly grated Parmesan.
Recipe details
- Prep time: about 10 minutes
- Cook time: about 1 hour 10 minutes (including roasting)
- Total time: about 1 hour 20 minutes
- Serves: 6
Tomato Basil Soup Recipe
Ingredients
- 4 pounds plum tomatoes (Roma), halved lengthwise
- 6 cloves garlic, peeled
- 3 tablespoons olive oil
- 2 teaspoons salt, divided
- 1 teaspoon freshly ground black pepper
- 1 tablespoon butter (or dairy-free alternative)
- 2 onions, sliced
- 56 oz whole peeled tomatoes (two 28-oz cans), juices reserved
- 1 cup fresh basil leaves, plus more for serving
- 3½ cups low-sodium vegetable broth (or water or chicken broth), plus more as needed
- 1 teaspoon granulated sugar (optional)
- 1 teaspoon red chili flakes (optional, to taste)
- Heavy cream or coconut milk, for serving (optional)
- Croutons or crackers, for serving (optional)
Instructions
- Roast the tomatoes: Preheat oven to 425°F. Arrange halved tomatoes and whole garlic cloves on baking sheets in a single layer. Drizzle with 2 tablespoons olive oil and season with salt and pepper. Roast until tomatoes are tender and beginning to burst: about 40–45 minutes for Roma, or 18–25 minutes for cherry tomatoes.
- Cook the onions: In a large pot, heat remaining tablespoon olive oil and butter over medium heat. Add sliced onions and cook 15–30 minutes, stirring often, until soft and caramelized.
- Combine: Add canned tomatoes (with juices), basil, broth, sugar (if using), and red chili flakes to the pot. Bring to a gentle simmer. When roasted tomatoes are done, add them with their juices and return the mixture to a simmer.
- Simmer: Cook uncovered over low heat for about 20 minutes to blend flavors.
- Blend: Carefully puree the soup in batches in a blender or with an immersion blender until smooth. Return soup to the pot and taste for seasoning—add salt and pepper as needed.
- Serve: Garnish with fresh basil, a drizzle of cream or coconut milk if desired, and croutons or crackers. Enjoy warm.
Notes
Using only fresh tomatoes: If you prefer not to use canned tomatoes, double the quantity of fresh tomatoes called for. To peel fresh tomatoes quickly, blanch in boiling water for about 30 seconds, then transfer to ice water; the skins will slip off easily.
Freezing: This soup freezes well if dairy is omitted. If you add cream, wait to add it after reheating.
Originally posted January 2016.
