Roma tomatoes—the same variety prized for Italian sauces—make an exceptionally rich and flavorful soup. These meaty plum tomatoes have less water and more flesh than other varieties, resulting in a naturally thick, intensely tomatoey soup. Roasting caramelizes their sugars and deepens the flavor. A swirl of butter at the end creates silky richness. This is tomato soup the way it should be.
Why This Recipe Works
Roma tomatoes are engineered by nature for cooking. Their low moisture content means you get more tomato flavor per pound, and the soup comes together thick without long reduction. Roasting concentrates these qualities further, creating caramelized depth that raw or simmered tomatoes can't match. The butter finish—a French technique—adds luxurious body.
Understanding Roma Tomatoes
Also called plum tomatoes or Italian tomatoes, Romas were developed specifically for cooking. They have fewer seeds, less juice, and more flesh than round tomatoes. San Marzano—the famous canned Italian tomatoes—are a type of Roma. When fresh Romas are in season, they make extraordinarily good soup. Even out of season, they're often the best choice at the supermarket.
Step-by-Step Guide
Halve the tomatoes lengthwise and place them cut-side up—this allows maximum caramelization. Roast the onion and garlic alongside for a one-pan flavor base. The tomatoes are ready when they've collapsed, concentrated, and show golden-brown edges.
Transfer everything to a pot with the broth and herbs. A brief simmer melds the flavors. Blend until perfectly smooth—Romas make an especially velvety puree. The butter goes in at the end, off the heat, to emulsify into silky richness.
Serving Suggestions
Serve with crusty Italian bread or grilled cheese on sourdough. The Parmesan garnish is essential—use real Parmigiano-Reggiano for best results. This soup also makes an excellent base for shakshuka or pasta sauce. Pairs beautifully with a simple Caesar salad.
Variations to Try
- Tuscan style: Add white beans and rosemary
- Vodka sauce version: Add a splash of vodka and cream
- Roasted garlic: Roast a whole head of garlic and blend in
- Sun-dried boost: Add 1/4 cup sun-dried tomatoes for intensity
Roma Tomato Soup
Nutrition (per serving)
Ingredients
Instructions
- Roast vegetables. Preheat oven to 400°F. Halve Roma tomatoes lengthwise and place cut-side up on a baking sheet with onion quarters and garlic. Drizzle with olive oil and season with salt. Roast for 20-25 minutes until caramelized.
- Simmer. Transfer roasted vegetables to a large pot. Add chicken broth, dried oregano, and thyme. Simmer for 10 minutes.
- Blend. Use an immersion blender to puree until smooth. The soup should be thick and rich. Add more broth if needed.
- Finish. Stir in butter until melted and incorporated. Season with salt and pepper.
- Serve. Ladle into bowls. Garnish with fresh oregano and freshly grated Parmesan cheese.
Recipe Notes
- Choose firm, deep red Roma tomatoes for best flavor
- Roast cut-side up for maximum caramelization
- Add butter off heat to emulsify properly
Frequently Asked Questions
Why are Roma tomatoes best for soup?
Roma tomatoes (also called plum tomatoes) have less water and more flesh than other varieties. This means more concentrated tomato flavor and a naturally thicker soup without excessive reduction.
Can I use canned Roma tomatoes?
Yes! San Marzano tomatoes (a type of Roma) are excellent canned. Use two 28-oz cans of whole peeled San Marzano tomatoes. Skip the roasting and simmer directly with the sautéed aromatics.
Why roast the tomatoes cut-side up?
Roasting cut-side up allows the moisture to evaporate and the natural sugars to caramelize. Cut-side down would trap moisture and steam the tomatoes instead of roasting them.
What does the butter add?
Butter adds richness and a silky mouthfeel to the finished soup. It also helps balance the acidity of tomatoes. This classic French technique creates a more luxurious texture.
How do I know when Roma tomatoes are ripe?
Ripe Roma tomatoes should give slightly when pressed and have deep red color. They should smell fragrant at the stem end. Avoid any with soft spots or wrinkled skin.