A delicious low carb tomato soup that's rich and full of flavour without the need for any stock cubes. It's an ideal recipe if you're inundated with homegrown tomatoes as we'll roast a batch along with oil, basil and garlic. I'll also show you a tomato soup Slimming option and how to make this tomato soup in a soup maker.

Close up of a white bowl full of keto creamy tomato soup and fennel, olive oil and plant based cream

One of my favourite Winter recipes is this tasty roasted tomato soup. I know there's lots online, but the best homemade tomato soup is with fresh tomatoes.

AND, I must show you show to roast tomatoes for soup. If you skip this key step, it'll be weak and bland, unless you add sugar. You see, roasting tomatoes concentrates the sweeter taste.

I've only just realised, it's also a Vegan roasted tomato soup. Hint, the creamy texture I gave it was from Elmlea's plant based cream. But, you could of course, use a dollop or quark or low fat cheese for an unofficial Slimming World soup.

Vegan roast tomato soup served in a white Denby bowl, topped with herbs, ready to eat

Roasting Tomatoes for Soup

It may sound a little faffy initially, but I highly recommend you not skipping the oven roasted element in this tomato soup recipe. I guarantee you'll taste the difference if you don't.

Remember, the oven will do all the work for you. It is optional if you want to skin the tomatoes first by resting in boiling water.

I've made this tomato so many times and it tastes just as amazing with them on. Shreds of skin just does not bother me. In fact, it adds a bit of texture. You can also roast any type of tomatoes. I had a mix of large to cherry tomatoes and simply roasting them all together.

Picture on how to roast tomatoes for soup using a large metal making tray, topped with garlic, sea salt and olive oil

How to Make Roasted Tomato Soup in a Soup Maker

Firstly, you'll find a list of tomato basil soup ingredients in a printable checklist towards the bottom of this page. All I do is:

Preheat your oven on Gas Mark 5 / 375F / 190c or 170 fan
Halve all of your tomatoes and place them on a large baking tray and sprinkle with salt, pepper, garlic, dried basil and olive oil
For unofficial Slimming World tomato soup: swap olive oil for a few sprays of Fry Light or other low calorie cooking oil spray
Roast in the oven for 50 minutes
Meanwhile, saute the onion in a large frying pan or saute soup maker function
Then transfer the roasted tomatoes into the soup maker, along with the remaining ingredients, except the water, making sure you scrape every bit off the tray as it all adds to the flavour
Add the water LAST. That's because each tomato cooks and shrinks at different speeds and you may need a little more or less
Set your soup maker to smooth, then blend and season again to taste before serving with your favourite toppings!

Picture of the best roast tomato soup using homegrown tomatoes in a white bowl

Stove Stop Tomato Soup Method

Follow exactly the same method as above, but instead of adding tomato soup to a soup maker, transfer to a large saucepan.

Then simmer and blend for around 20-25 minutes before blending and serve.

You can see below for my favourite soup toppings for low carb tomato soup.

Finished roast tomato soup made in a soup maker

How Is This a Keto Tomato Soup?

The reason this is a keto creamy tomato soup as part of a low carb diet is because it uses:

kidney beans as opposed to potato
Olive oil
Plant based cream
Note: you could also use frozen cauliflower instead of kidney beans*

Note: a Keto diet relies more on a Mediterranean diet that's low in carbs as opposed to low in fat. Healthy fats such as olive oil, nuts, cheese, butters, avocados are allowed. Satiety is believed to be key, making it a more sustainable diet, whereas our bodies can turn carbs into fat.

You might find that a low-fat diet isn't working for you right now despite doing lots of exercise. You can read more here as to why I started the Fast 800 diet alongside intermittent fasting and have been losing weight again.

Low Fat Tomato Soup Option

Disclaimer: This is an unofficial page and has no affiliation or endorsement from Slimming World. Slimming World's website can be found at https://www.slimmingworld.co.uk/
*Any syn values are personal estimates and not verified by Slimming World.

I've also made this tomato soup Slimming friendly SO many times. In fact, you'll find over 80 free unofficial Slimming World soup recipes on my blog here.

But if you're not looking for a low carb tomato soup, then you can make the following changes:

Swap olive oil for Fry Light
Add a low fat cream or use cheese as part of your allowance
Top with healthy croutons
Always uses fresh herbs as a garnish. (If you cook with them too soon, you'll kill the taste)
If you're not eating a low carb diet, you can simmer 200g diced potato in the pot until tender
Adding a dash of balsamic vinegar is also makes a delicious tomato soup

Soup Maker I Use

I highly recommend the Morphy Richards original soup maker. I am in no way connected with them and been using mince since 2013.

Occasionally, you'll find some ingredients will catch at the bottom. If you ever encounter this, then see my guide on how to remove burnt food from a soup maker.

Since 2020, I've upgraded to the saute soup maker (and made this soup in it). I then donated my original one to my Mum as it's still going strong. I love the saute function, meaning there's less washing up. Also, if you find you've forgot to add an ingredient, you can remove the lid and the machine remembers it was in the middle of cooking soup.

Both of these machines cook between 1300-1600ml to make soup for 4 people. This also makes it ideal for freezing tomato soup when I have leftovers.

Can I Freeze Tomato Soup?

Yes, you can freeze this tomato soup with no problems. I always freeze in Sistema containers for up to 3 months. I'll then fully defrost and microwave straight in the tub until piping hot.

How Long Does Roast Tomato Soup Keep?

When storing roasted tomato soup in the fridge, it's best to eat it within 3 days. Sometimes I've got away with 5 days before it's started to turn bad. Any longer than this, it is best to keep it in the freezer just in case.

Low Carb Tomato Soup (Keto) + Low Fat Options