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keto tomato soup
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5 from 1 vote

Keto Tomato Soup

This Keto Tomato Soup is simple to make, super creamy, and is made with fresh roasted tomatoes, basil, and parmesan cheese. You only need a few ingredients to make this perfect soup!
Prep Time10 mins
Cook Time45 mins
Total Time55 mins
Course: Soup
Cuisine: American
Keyword: tomato
Servings: 16 servings
Calories: 121kcal
Author: Briana


  • 4 pounds tomatoes, quartered (Roma, plum, beefsteak, or cherry. Can be substituted for canned tomatoes, see notes)
  • 2 medium yellow onions, quartered
  • 2 tablespoons olive oil
  • 4 teaspoons kosher salt, divided (to taste)
  • 4 tablespoons unsalted butter
  • 8 cloves garlic, minced
  • 2 teaspoons Italian seasoning
  • 4 cups chicken broth
  • handful of fresh basil (optional)
  • 8 ounces heavy cream
  • freshly grated parmesan cheese to taste
  • olive oil, heavy cream, salt, pepper, parmesan & basil to garnish


  • Preheat the oven to 425°F. Add tomatoes and onions to a baking sheet. Toss with olive oil, salt, and pepper. Roast for 30 minutes, until the tomatoes begin to wrinkle and char. (If using canned tomatoes, skip to step 2).
  • In a stockpot over medium heat, melt butter. Add garlic cloves, and move around frequently to cook garlic until fragrant, about 1 minute. (If using canned tomatoes, add onions alongside the garlic with a big pinch of salt, and cook until onions are softened and translucent about 5 minutes.)
  • Once the garlic is fragrant, immediately add the tomatoes and onions to cool off the garlic to prevent it from burning. Add in broth or stock, along with salt, pepper, and Italian seasoning. Bring mixture to a boil, then reduce to a simmer and cover. Allow mixture to simmer for 10 minutes.
  • Add in optional basil, and stir to wilt. Using a blender or an immersion blender, blend the mixture until smooth.
  • Reduce heat to low, then stir in heavy cream if using to warm through. Slowly add in freshly grated parmesan cheese in batches, and stir to melt completely before adding more cheese.
  • Adjust seasonings to taste, then serve with heavy cream, olive oil, salt, pepper, basil, and parmesan. Enjoy!
  • Store leftovers in an airtight container in the fridge for up to 5 days.


  • To substitute for canned tomatoes, simply skip the tomato roasting step, and saute onions and garlic together before adding canned tomatoes (with liquid) to the stock pot. Continue on with the remaining steps. 
  • Be careful not to heat soup with cream or cheese too quickly, as it can curdle the dairy or cause cheese to clump together. 


Calories: 121kcal | Carbohydrates: 7g | Protein: 2g | Fat: 10g | Saturated Fat: 5g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 0.1g | Cholesterol: 25mg | Sodium: 810mg | Potassium: 323mg | Fiber: 2g | Sugar: 4g | Vitamin A: 1246IU | Vitamin C: 17mg | Calcium: 34mg | Iron: 1mg