This creamy keto tomato soup is made with fire-roasted tomatoes, pesto, heavy cream, and a simple low-carb thickener. It’s rich, smooth, and easy to make in one pot without sugar, flour, or cornstarch.
Cook the onion: Melt the butter in a large saucepan over medium-low heat. Add the onion and cook for 2–3 minutes, until softened and translucent.
Add the garlic: Stir in the garlic and cook for about 30 seconds, until fragrant.
Add the tomatoes: Pour in the fire-roasted tomatoes with their liquid
Season and simmer: Add the pesto, water, Better Than Bouillon, Italian seasoning, and black pepper. Stir to combine and simmer for 10 minutes.
Add the creamy ingredients: Stir in the xanthan gum, cream cheese, heavy cream, and Parmesan cheese.
Blend until smooth: Use an immersion blender to blend the soup directly in the pot until smooth and creamy. If using a standard blender, carefully transfer the soup to the blender and blend in batches as needed.
Season and serve: Taste and add salt as needed. Serve warm.