Creamy Keto Tomato Basil Soup

The Creamy Keto Tomato Basil Soup is a velvety, comforting dish made without sugar or flour, perfect for those following a keto lifestyle. This soup features the rich creaminess of heavy cream, the bold freshness of Roma tomatoes and basil, and the depth of flavor from garlic and quality broth. Roasting and then blending the tomatoes with herbs and cream creates a smooth, luxurious texture that is both low-carb and high in healthy fats, giving you all the cozy flavor of classic tomato soup while staying keto-friendly.

Course Appetizer, Main Course, Soup

Cuisine American, Italian-Inspired

Keyword basil, gluten free, grain free, keto, low-carb, tomato soup

Prep Time 15

Cook Time 35

Total Time 50

Servings servings

Calories 240kcal

Equipment

rimmed baking sheet
Large Pot
immersion blender
Knife
Cutting board

Ingredients

For the creamy tomato basil soup

2 pounds Roma tomatoes, halved lengthwise
3 tablespoons olive oil divided
4 cloves garlic, peeled
1/4 cup yellow onion, finely chopped
2 cups low-sodium chicken broth or vegetable broth
3/4 cup heavy whipping cream
1/4 cup fresh basil leaves, packed and chopped plus more for garnish
2 tablespoons unsalted butter
1/2 teaspoon dried oregano
1/4 teaspoon crushed red pepper flakes optional, for gentle heat
3/4 teaspoon fine sea salt or to taste
1/4 teaspoon freshly ground black pepper or to taste

Optional toppings

2 tablespoons grated Parmesan cheese for serving, optional
2 tablespoons sour cream or crème fraîche for serving, optional

Instructions

Preheat the oven to 400°F and line a rimmed baking sheet with parchment paper.
Arrange the halved Roma tomatoes cut side up on the prepared baking sheet and tuck the peeled garlic cloves among the tomatoes.
Drizzle the tomatoes and garlic with half of the olive oil and season lightly with a pinch of salt and pepper.
Roast until the tomatoes are soft, slightly caramelized at the edges, and the garlic is tender and fragrant, about 25 minutes.
While the tomatoes roast, heat the remaining olive oil and the butter in a large pot over medium heat.
Add the chopped onion and cook, stirring occasionally, until soft and translucent, about 4 to 5 minutes.
Stir in the dried oregano and red pepper flakes and cook until fragrant, about 1 minute.
Transfer the roasted tomatoes and garlic along with any juices from the baking sheet into the pot with the onions.
Pour in the chicken broth and bring the mixture to a gentle simmer over medium heat.
Simmer uncovered for 8 to 10 minutes to let the flavors meld and the tomatoes break down further.
Remove the pot from the heat and carefully blend the soup with an immersion blender until completely smooth and velvety.
Return the pot to low heat, stir in the heavy cream and chopped fresh basil, and warm gently without letting the soup boil.
Taste and season with the remaining salt and black pepper, adjusting to your preference.
Ladle the soup into bowls and top with extra basil, grated Parmesan, or a dollop of sour cream if using.

Notes

For an even deeper flavor, roast the tomatoes a little longer until more caramelized, watching carefully so they do not burn. To keep the soup ultra smooth, strain it through a fine mesh sieve after blending, though this step is optional and may slightly reduce fiber. For a dairy-free variation, replace the heavy cream with full-fat coconut cream and skip the Parmesan and sour cream toppings. The soup stores well in the refrigerator for up to 4 days and can be frozen for up to 3 months; reheat gently over medium-low heat without boiling to preserve the creamy texture.

Nutrition