Free Grocery Guide
tomato italian sausage and fennel soup

Tomato, Sausage, and Fennel Soup

dairy free gluten free low carb main course paleo recipes soups vegan

This aromatic and hearty recipe features a hat-trick of fennel: from the tender bits of fresh fennel bulb, to the infusion of ground fennel seed, and finally, the fennel-laced Italian sausage. 

This recipe happens to be gluten-free, dairy-free, Paleo, and low-carb, but feel free to make adaptations as it suits your dietary needs (recommendations below).  

While you don't have to make your own, I do recommend using my recipe for homemade Sweet Italian Sausage to make this soup extra divine. It's 100% free of funky, artificial ingredients you might find in the factory-made stuff, and 100% delicious.

Full disclosure: Some of the links in this post may be affiliate links. As an Amazon Associate, I earn from qualifying purchases. If you choose to purchase a product using one of these links, it will support my work at no additional cost to you.




Chef's Notes:

This recipe was originally inspired by “Tomato Soup with Two Fennels,” from Molly Wizenberg’s foodoir, A Homemade Life. After so many incarnations and additions, I think I can safely claim this version as my own. Still, I think of Molly's wonderful, well-tested recipes every time I make it.

Fennel, with its crisp licorice perfume, is like a flavor cousin to basil (another tomato lover). It’s also a key ingredient in my Sweet Italian Sausage, which is featured in this tasty pot. It's that triple-hit of fennel, from fresh, seeds, and the sausage, that elevates the flavor of this soup. 

A note about nightshades: Tomatoes, obviously, are one of the main ingredients in this soup. While tomatoes have plenty of health benefits, they are in the nightshade family and should be avoided by those who are sensitive to nightshades, or those who are on a strict elimination diet like AIP.

If you happen to be in the no-nightshade camp, check out some of my nightshade-free soup recipes like Turkey Albondigas, or Creamy Carrot Coconut Soup


  • Optional garnishes: Wispy fennel fronds, chopped fresh parsley, basil ribbons, or fresh thyme leaves.
  • Hearty version (non-Paleo): Add one 15-oz. can of cannellini beans, rinsed and drained, during the last 5 minutes of cooking.
  • Vegan version: Replace chicken stock with vegetable broth. Omit sausage. Add one 15-oz. can of cannellini beans, rinsed and drained, during the last 5 minutes of cooking.



Thyroid-healthy Recipe Highlights:


If you're anything like me, when I started down the path of thyroid-healthy eating I had questions-- lots of them. What I didn't have was a step-by-step system, to get me where I wanted to go. I created the Thyroid-healthy Meal Plan Kickstart to take YOUR healing journey farther, FASTER. It includes recipes, resources, and a 4-week roadmap to get you where you want to go! Learn more HERE.


More Thyroid-healthy Soup Recipes:


Tomato, Sausage, and Fennel Soup

Tomato, Sausage, and Fennel Soup

Yield: 6
Author: Ginny Mahar
Prep time: 30 MinCook time: 30 MinTotal time: 1 Hour
Gluten-free, Dairy-free, Paleo, Low-Carb, Keto. Includes Vegan option (see notes).


  • 1 lb. Sweet Italian Sausage
  • 2 teaspoons extra virgin olive oil
  • 1 small onion or large shallot, diced small
  • 1 medium fennel bulb, diced small
  • 4 cloves garlic, minced
  • 1 large (or 2 medium) carrots, peeled and diced small
  • 4 stalks celery, diced small
  • 1 1/4 teaspoons ground fennel seed
  • 2 teaspoons chopped fresh thyme
  • 4 cups chicken stock, preferably homemade
  • 28 oz can whole peeled tomatoes, preferably San Marzano
  • sea salt and freshly ground black pepper, to taste


  1. Place Italian sausage in a large (5-quart) soup pot over medium-high heat. Cook until browned and most liquid has evaporated. Remove from pot, drain and discard drippings, and set aside.
  2. Add olive oil to pot over medium heat. Add fennel, garlic, onion, carrots, and celery, and cook 10 - 15 minutes or until carrots are tender. Feel free to add a splash of chicken stock to speed the process along by creating steam.
  3. Add ground fennel and fresh thyme and stir to combine. Pour in chicken stock and bring to a simmer.
  4. Meanwhile, place tomatoes in a blender and process to your desired consistency ("crushed" style recommended). Add to soup pot along with cooked sausage. Season with salt and pepper and simmer, covered, for 30 minutes or until flavors have melded. Taste and adjust seasoning as desired.


  • Optional garnishes: Wispy fennel fronds, chopped fresh parsley, basil ribbons, or fresh thyme leaves.
  • Vegan version: Omit sausage. Replace chicken stock with vegetable broth. Add one 15-oz. can cannellini beans, rinsed and drained, during last 5 minutes of cooking.
  • Hearty version (non-Paleo): Add one 15-oz. can cannellini beans, rinsed and drained, during last 5 minutes of cooking. 

Nutrition Facts



Fat (grams)


Sat. Fat (grams)


Carbs (grams)


Fiber (grams)


Net carbs


Sugar (grams)


Protein (grams)


Sodium (milligrams)


Cholesterol (grams)

Did you make this recipe?
Tag @hypothyroidchef on Instagram and hashtag it #hypothyroidchef

Classic Braised Short Ribs

Nov 30, 2022

Gratitude: It's More Than Just Being Thankful

Nov 23, 2022

Navigating Holiday Food the Thyroid-healthy Way

Nov 17, 2022

Olive Oil Mashed Cauliflower & Sweet Potatoes (AIP, Paleo)

Nov 01, 2022

Get the Thyroid-healthy Grocery Guide!

Want to feel better but aren't sure where to begin? This handy 1-page Grocery Guide is a great place to start. Choose from over 130 delicious thyroid-healthy foods. Download your copy and start your healing journey today!

Download Your FREE Guide Today

I don't send spam. Unsubscribe at any time.