Skip the bread bowl. This Keto Tomato Basil Soup brings big Italian energy with zero pasta guilt. It’s creamy, herby, and shockingly satisfying—like a hug from Nonna who also tracks her macros.
You’ll blitz it in one pot, drizzle on some olive oil, and boom: restaurant vibes at home. Want comfort food with a six-pack? This is how you cheat without cheating.
What Makes This Recipe Awesome
- Ultra low-carb, high flavor: Rich tomato, garlic, and sweet basil with no sugar traps—only smart fats and fresh herbs.
- Ready in under 30 minutes: Weeknight-friendly but weekend-worthy.
- Silky without flour: Heavy cream and a little butter deliver that luxurious, velvety finish.
No roux required.
- Meal prep gold: Reheats like a champ and actually tastes better the next day.
- Customizable: Want more protein? Add Italian sausage or shredded chicken. Want more zing?
Dial up the chili flakes.
What Goes Into This Recipe – Ingredients
- 2 tablespoons olive oil
- 1 tablespoon unsalted butter
- 1 small yellow onion, finely chopped
- 3–4 cloves garlic, minced
- 1 (28-ounce) can whole peeled tomatoes (San Marzano style preferred)
- 2 tablespoons tomato paste (no sugar added)
- 2 cups low-sodium chicken broth (or vegetable broth)
- 1/2 teaspoon red pepper flakes (optional, for heat)
- 1 teaspoon dried oregano
- 1 teaspoon smoked paprika (optional but amazing)
- 1 teaspoon sea salt (plus more to taste)
- 1/2 teaspoon black pepper
- 1/2 cup heavy cream
- 1/2 cup freshly grated Parmesan
- 1 cup fresh basil leaves (loosely packed, plus extra for garnish)
- 1–2 teaspoons sweetener (optional) (erythritol/monk fruit) to balance acidity
- Extra-virgin olive oil for finishing
Let's Get Cooking – Instructions
- Sauté the aromatics: Heat olive oil and butter in a large pot over medium heat. Add onion and cook 5–6 minutes until translucent. Stir in garlic and cook 30 seconds until fragrant (don’t burn it—burnt garlic = sadness).
- Build the base: Add tomato paste, oregano, smoked paprika, red pepper flakes, salt, and pepper.
Stir 1 minute to toast the paste and spices—this deepens flavor like magic.
- Add tomatoes and broth: Pour in the canned tomatoes (with juices) and the chicken broth. Break up tomatoes with a spoon. Bring to a gentle boil, then reduce to a simmer for 12–15 minutes.
- Balance the acidity: Taste.
If it’s too tangy, add 1–2 teaspoons keto-friendly sweetener. This doesn’t make it sweet; it just rounds it out. FYI, Parmesan will also mellow sharpness later.
- Blend it smooth: Stir in the fresh basil.
Use an immersion blender to puree until silky. No immersion blender? Carefully transfer to a countertop blender in batches, vent the lid, and blend until smooth.
- Creamy finish: Return soup to low heat.
Stir in heavy cream and Parmesan. Simmer 2–3 minutes until slightly thickened and glossy. Adjust salt and pepper.
- Serve like a pro: Ladle into bowls, drizzle with extra-virgin olive oil, add a basil chiffonade, and dust with extra Parmesan.
Optional: a dollop of pesto or a few crispy prosciutto shards for the win.
How to Store
- Fridge: Cool completely, then store in an airtight container for up to 4 days.
- Freeze: Skip the cream if freezing. Freeze the base up to 3 months, then add cream and Parmesan after reheating for best texture.
- Reheat: Warm gently on the stove over low heat, stirring. If it thickens too much, splash in broth or a bit of cream.
Benefits of This Recipe
- Keto-aligned macros: Minimal net carbs with satisfying fats to keep you full and focused.
- Anti-inflammatory ingredients: Tomatoes and basil bring lycopene, vitamin C, and antioxidants to the party.
- Gut-friendly: No flour thickeners or sneaky sugars, so it’s lighter on digestion.
- Budget-friendly gourmet: Canned tomatoes + pantry spices = high-end flavor on a Tuesday.
- Flexible for families: Carb-eaters can add grilled cheese or croutons; you stay keto-strong.
Avoid These Mistakes
- Using sugary tomatoes: Read the label.
Choose canned tomatoes without added sugar; it matters for net carbs.
- Curdling the cream: Don’t add cream to boiling soup. Lower the heat first, then stir it in gently.
- Skipping the basil: Dried basil won’t deliver the same aroma. Fresh basil = essential.
- Under-seasoning: Tomatoes need salt.
Taste at the end, then season like you mean it.
- Over-blending hot soup in a sealed blender: Steam pressure can blow the lid. Vent it and blend in batches. Your ceiling will thank you.
Recipe Variations
- Roasted Tomato Upgrade: Roast fresh Roma tomatoes, onion wedges, and garlic with olive oil at 425°F (220°C) for 25–30 minutes.
Blend with broth and proceed—deeper, smokier flavor.
- Protein Boost: Brown Italian sausage or add shredded rotisserie chicken. Stir in at the end for a heartier bowl.
- Dairy-Free Creaminess: Swap heavy cream for full-fat coconut milk and use nutritional yeast instead of Parmesan. Different vibe, still cozy.
- Pesto Swirl: Stir in a spoonful of keto pesto at serving for an herby, garlicky punch.
- Spicy Arrabbiata Style: Double the chili flakes and add a pinch of cayenne.
For heat seekers only—consider yourself warned.
- Mascarpone Moment: Replace cream with 1/3 cup mascarpone for lush texture and subtle sweetness.
FAQ
Is tomato soup really keto?
Yes—when you control ingredients. Many store-bought soups have added sugar and starch. This recipe keeps net carbs low by using whole tomatoes, broth, cream, and cheese without thickeners.
Can I use fresh tomatoes instead of canned?
Absolutely.
Use about 2 pounds of ripe tomatoes. For best flavor, blanch and peel or roast them first to concentrate sweetness and reduce excess water.
How can I make it thicker without flour?
Simmer a bit longer to reduce, add an extra tablespoon of tomato paste, or blend in 1–2 ounces of softened cream cheese. All are keto-friendly, IMO.
What can I serve with this on keto?
Try almond-flour biscuits, cheese crisps, a side salad with olive oil and lemon, or grilled halloumi.
If you want extra protein, pair with baked chicken thighs.
Can I skip the Parmesan?
You can, but it adds umami and balances acidity. If avoiding dairy, use a tablespoon of nutritional yeast and an extra pinch of salt to compensate.
Why add sweetener to a savory soup?
Tiny amounts of keto-friendly sweetener don’t make it sweet; they smooth out tomato tang. It’s a chef trick, not dessert in disguise.
Will an immersion blender make it perfectly smooth?
Close.
For ultra-silky texture, a countertop blender is superior. Just remember to vent the lid to avoid a tomato geyser.
My Take
This Keto Tomato Basil Soup punches way above its ingredient list. It tastes indulgent, cooks fast, and keeps carbs in check—basically the dream trifecta for busy people who still want legit flavor.
The fresh basil and Parmesan do the heavy lifting, and the cream brings the mic-drop finish. Make a double batch; future you will be very, very pleased.
