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Dare I say it? This is the only tomato basil soup recipe you’ll ever need. It’s one of my husband Ryan’s favorite meals – and it’s so easy to make! THM S Helper
See the recipe below for instructions on how to make some toasted cheese melts to go with the soup!
To stay lower carb, try making a quick cheese quesadilla using a low carb tortilla and your favorite cheese! I also like to smear a little pesto inside the tortilla to echo the basil in the soup.
A note on fuel type
For THM fuel type I’m going to call this an S Helper. It’s not a full blown Crossover if you allow for some tomatoes in an S meal, but it is a lot of tomato for a straight S. If you add the toasted cheese melts (see how in the recipe instructions below) this would be a THM XO meal.
I could’ve tried to cut down the fat for a more THM E-ish soup but I wanted a full on delicious tomato basil soup for my repertoire. Right now I’m often either pregnant or nursing so S Helpers and Crossovers are my jam – and they’re great for hungry husbands and growing children. If you want to try to cut back on the fat you could try using just a tablespoon of butter and try using low fat cottage cheese for creaminess in place of the whipping cream (it gets blended up anyway). If you do that you’d have a “light E” and should add a carb source on the side (like a slice of sprouted or sourdough toast) for a true THM E meal.
What is an S Helper?
A THM S Helper is a THM S meal (focusing on healthy fats) with just a few carbs added in – up to 15g net carbs. It’s not a straight S meal, but it’s not a full blown crossover of carbs and fats. While it may not be quite as weight loss promoting as a simple THM S, there’s nothing wrong with an S Helper every once in awhile to switch things up!
Don’t forget the basil!
Basil is my favorite fresh herb. Last year I found some basil plants at Walmart so I grew one in my flowerbed and one in a pot. The flowerbed plant is currently dead and covered in a foot of snow, but the potted basil plant is sunning itself in front of my patio windows.
You can’t beat fresh basil! (Or fresh basil that has been frozen when you have an overabundance.) Grow your own, check a farmer’s market, or buy one of those dinky packs at Walmart for way too much money.
Just kidding… If you don’t have fresh basil, you can also use basil puree – I tried Aroma One Organics Basil Puree (in a tube) from Walmart. Find it near the spices for around $3. I used 2 tablespoons, and you can always add more if you prefer. (I think I’ve seen a similar product at Aldi too.)
You could also try using a good pesto! I love Aldi’s green pesto. In a pinch you could use dried basil. Add any of these substitutes to taste – you definitely won’t need half a cup.
As always, check out the Notes section of the recipe for helpful info and answers to frequently asked questions!
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There is a tomato basil soup recipe in Necessary Food, my first cookbook, but this one is a complete remake and quite honestly the only tomato basil soup recipe you’ll ever need.

Tomato Basil Soup
- Total Time: 35 minutes
- Yield: a little over 5 1.5-cup servings
Description
For THM fuel type I’m going to call this an S Helper. It’s not a full blown Crossover if you allow for some tomatoes in an S meal, but it is a lot of tomato for a straight S. If you add the toasted cheese melts (see how in the recipe instructions below) this would be a THM XO meal. I could’ve tried to cut down the fat for a more THM E-ish soup but I wanted a full on delicious tomato basil soup for my repertoire. It’s one of my husband Ryan’s favorites and so easy. Right now I’m often either pregnant or nursing so S Helpers and Crossovers are my jam – and they’re great for hungry husbands and growing children. If you want to try to cut back on the fat you could try using just a tablespoon of butter and try using low fat cottage cheese for creaminess in place of the whipping cream (it gets blended up anyway). If you do that you’d have a “light E” and should add a carb source on the side (like a slice of sprouted or sourdough toast) for a true THM E meal. (Note: the cottage cheese may get grainy if you really cook it. Don’t boil the soup before blending it, and try not to overcook it.)
Ingredients
- 4 tablespoons salted butter
- 1 medium onion (sliced)
- 1/2 cup oat fiber
- 2 28-ounce cans crushed tomatoes (I got mine at Aldi and they had a bit of salt added)
- 2 cups water (hint: use the water to clean out your tomato cans before adding to the soup to get all the goodness!)
- 1/2 cup heavy whipping cream
- 1/2 cup loosely packed fresh or frozen basil leaves (see alternatives below)
- 1/3 cup collagen
- 2 teaspoons chicken bouillon
- 1 teaspoon baking soda
- 1 teaspoon THM Super Sweet Blend
- 1 teaspoon garlic powder
- 1/2 teaspoon black pepper
- 1 teaspoon salt (to taste – may vary depending on your ingredients)
Instructions
Sauté the onion in the butter in a non-reactive pot – an enamel coated Dutch oven works great (and stainless steel is fine too). Sauté until the onion is brown and wilted. Add the oat fiber and stir to coat the onions.
Add the rest of the ingredients (except the salt). Blend with an immersion blender or a regular blender until smooth. (You can probably get a smoother texture with a regular blender, but I usually use my immersion blender because it’s easier with less clean up. Be careful if using a regular blender. Blending hot liquids can cause pressure buildups so be very careful and vent the blender as needed.) Tip: if using an immersion blender, blend before the soup boils so you don’t have to contend with spattering hot tomato while you’re trying to blend. Add salt to taste after blending.
Bring the soup to a boil. Turn the heat down and simmer for 15 minutes; cover the pan but leave the lid cracked. Taste and adjust as needed. Serve.
How to make toasted cheese melts (THM XO): place slices of sprouted bread (I like Aldi’s) on a sheet pan. Spread the top of each with mayo (you can use butter, but I prefer mayo) and top with garlic powder and shredded cheddar cheese. Broil in the oven until the cheese is melted. (Don’t toast them too much or they’ll dry out.) Serve with tomato basil soup!
To stay lower carb, try making a quick cheese quesadilla using a low carb tortilla and your favorite cheese! I also like to smear a little pesto inside the tortilla to echo the basil in the soup.
Notes
Tip: if using frozen basil leaves, measure them before they thaw or else they’ll really wilt and you won’t get an accurate measurement.
The collagen is just there for protein. Feel free to leave it out if you add protein to your meal in some other way.
Oat fiber: This is a really fine, dry, low carb flour that I like to use for thickening soups and gravies. I don’t know of any great substitutes, but some people use psyllium husk flakes in its place. Oat fiber can usually only be found online. Use gluten free oat fiber for a gluten free option. Oat fiber and oat flour are different and are not interchangeable.
Basil: fresh basil really makes this soup amazing. If you don’t have it you can also use basil puree – I tried Aroma One Organics Basil Puree (in a tube) from Walmart (picture above in post). Find it near the spices for around $3. I used 2 tablespoons, and you can always add more if you prefer. (I think I’ve seen a similar product at Aldi too.) You could also try using a good pesto! I love Aldi’s green pesto. In a pinch you could use dried basil. Add any of these substitutes to taste – you definitely won’t need half a cup.
Chicken bouillon: I use Better than Bouillon chicken bouillon from Walmart. You could probably use 2 cups of chicken stock in place of the water and chicken bouillon, but you’ll need to increase the salt and seasonings.
Baking soda: this just helps the tomato soup not be so acidic with a more rounded flavor.
THM Super Sweet Blend: use your favorite low glycemic sweetener to taste in place of this if desired.
Allergies: gluten free (use gluten free oat fiber and watch the bouillon ingredients), egg and nut free (again, watch the bouillon ingredients). To make the soup dairy free, use refined coconut oil or olive oil in place of the butter, cream up the soup with full fat coconut milk in place of the whipping cream, and use a df bouillon (or broth in its place).
- Prep Time: 10 mins
- Cook Time: 25 mins
- Category: Soup
- Method: Stovetop
- Cuisine: THM S Helper
Keywords: thm, trim healthy mama, thm tomato soup, healthy tomato soup, homemade tomato soup recipe
Yum! I just made a very similar soup for lunch this week at the request of our daughter for her birthday lunch, and Grandpa, who often says we eat too healthy for his liking ;), sheepishly took seconds. I wasn’t quite sure what I did to it, though, because I’m notorious for just throwing things together and not being able to recreate dishes.
But I’m saving this one so our kids will be able to have a starting base, and I’ll be able to recreate a soup everyone loved – thanks for sharing this! (And I always forget to use that collagen sitting on the shelf! Great idea to put in a soup!!)
I am making this yummy soup for the second time. It is near -40 wind chill temp in Nebraska. I used my frozen home grown tomatoes and added 2 TBS of Instant Cheese Sauce (FP version) from THF). Extremely delicious from the small taste I had – excited for lunch – grilled cheese sandwich (FP bread) for “dessert.” 😂
★★★★★
Oooh…that sounds like a delicious lunch!
Could the collagen be optional?
Yes, but you would need to add protein to your meal in some other way. 🙂