There’s nothing quite like the robust flavor of homemade roasted tomato sauce. That luscious caramelized flavor adds depth to so many dishes that you just don’t get with jarred sauce. And it’s astonishingly easy to make – four simple ingredients and a good blender is all you need.
Then you have a versatile sauce that can be used for keto pizza, keto meatball casserole, or myriad other low carb meals.
Every year around this time, my garden goes wild. The tomatoes are slow to come on, but when they do, they are bountiful. I find myself with far more than I can eat, and roasting them is my favorite way to preserve the harvest. I pack some into jars and freeze as is, and I make multiple batches Roasted Tomato Soup.
And this roasted tomato sauce is always top of my list. It stores and freezes well, so I can enjoy the fruits of my garden all year long.
Why you’ll love this keto-friendly sauce
I love how effortless this recipe is. No need to spend hours simmering the sauce on the stove! Your oven does all the heavy lifting.
- Unparalleled flavor: Roasting brings out the natural sweetness of tomatoes and intensifies the flavor.
- Simple ingredients: No preservatives or added sugars here!
- Easy to make: No need seed the tomatoes or simmer a pot on the stove, so this homemade sauce comes together much faster.
- Versatile: Think beyond just zucchini noodles and low carb pizza. This sauce is delicious with chicken or fish too. Or spoon some over keto meatloaf!
- Make ahead: You can make big batches in the summer and store it in jars in the freezer for months.
- Low carb: This recipe relies on the natural sweetness of the tomatoes, and has only 3.5 grams net carbs per serving.
Ingredient Notes
- Tomatoes: Fresh seasonal tomatoes have the best flavor, and any variety of red tomato works for this sauce. But off-season hothouse tomatoes can work too.
- Garlic: Fresh garlic is a must for this recipe.
- Olive oil: A good extra virgin oil pairs so well with tomatoes. But you can also use avocado oil.
- Red pepper flakes: This gives the sauce a tiny kick of spice.
- Salt and pepper
How to make Roasted Tomato Sauce
- Prep the tomatoes: Remove the stem and cut the tomatoes in quarters. There is no need to remove the seeds or liquid. Place in a large glass or ceramic baking dish.
- Drizzle and season: Add the garlic, olive oil, red pepper flakes, and salt and pepper. Toss to combine.
- Roast: Place in a hot oven and cook until the tomatoes are very soft and caramelized in spots.
- Blend: Transfer to a blender and blend until smooth.
- Serve or store: Use immediately or let cool and freeze for later.
Expert Tips
- Ripe seasonal tomatoes will give the sauce the best flavor, but you can make it year round with hot house tomatoes. You cannot use canned tomatoes for this recipe.
- There is no need to skin the tomatoes or remove the seeds. Much of the liquid will be released as they roast. Use just enough of this liquid to make the roasted tomatoes measure out to 3 cups before blending.
- If you prefer a chunkier sauce, simply pulse the blender a few times instead of blending completely smooth.
- Add fresh herbs like basil, thyme, or rosemary, just before blending the tomatoes.
To freeze:
Because tomatoes are highly acidic, it’s best to use glass jars or containers. But you will need to leave a bit of head room so that they don’t explode as the sauce freezes. I usually fill pint jars to within an inch of the top, and then I place them upright in the freezer with no lid.
Once they have frozen solid, I screw the lid on. They can remain in the freezer for up to a full year, without spoilage.
Frequently Asked Questions
To make roasted tomato sauce, the tomatoes should be roasted at 400ºF (200ºC) for 35 to 45 minutes. They are ready when they are very soft, and have spots where they have browned and caramelized.
Some jarred sauces are keto friendly, but many contain added sugars to intensify the sweetness. I recommend making your own so you know exactly what you are consuming. This Roasted Tomato Sauce fits well with the keto diet, although it’s always best to use moderation.
Store the sauce in a jar in the fridge for up to 5 days or in the freezer for up to 12 months.
Roasted Tomato Sauce Recipe
Ingredients
- 3 lb (1,360.78 g) fresh tomatoes
- 8 cloves garlic
- 1/3 cup (78.86 ml) olive oil
- 3/4 tsp salt
- 1/2 tsp black pepper
- 1/2 tsp red pepper flakes
Instructions
- Preheat the oven to 400ºF.
- Remove the stems and cores from the tomatoes and cut into quarters. If the tomatoes are very large, cut into eighths. Spread out in a large glass or ceramic baking dish.
- Coarsely chop the garlic cloves and add to the tomatoes.
- Drizzle with olive oil and sprinkle with the salt, pepper, and red pepper flakes. Toss to combine and then spread out evenly again in the dish.
- Roast 45 minutes, or until the tomatoes are browned and caramelized in spots. Remove and let cool for a few minutes.
- Using a slotted spoon, transfer the tomatoes to a blender. Add just enough of the liquid in the pan to measure out 3 cups total (tomatoes and juice). Blend until smooth.
Notes
Nutrition
Nutritional Disclaimer
Please note that I am not a medical or nutritional professional. I am simply recounting and sharing my own experiences on this blog. Nothing I express here should be taken as medical advice and you should consult with your doctor before starting any diet or exercise program. I provide nutritional information for my recipes simply as a courtesy to my readers. It is calculated using MacGourmet software and I remove erythritol from the final carb count and net carb count, as it does not affect my own blood glucose levels. I do my best to be as accurate as possible but you should independently calculate nutritional information on your own before relying on them. I expressly disclaim any and all liability of any kind with respect to any act or omission wholly or in part in reliance on anything contained in this website.
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I raise LOTS of tomatoes each year, and I have roasted tomatoes before, but I’m anxious to try this recipe, for it sounds scrumptious and can be used for sooo many other recipes! I know that I can freeze this, but do you have a recommendation for canning it? I love your information..it is so helpful!
Nevermind, Carolyn….I found my answers below in the comments! This is a great recipe!
This is my 2nd time making this (needed to use up all the tomatoes I had to pick last week before the freeze)! It’s so easy and so delicious! Can’t wait to make something yummy this week.
Easy and delicious! I added just a touch of fresh basil and oregano, a little bit of red bell pepper, and a little bit of onion. I did not have the pepper flakes, it was fine without them. I am fortunate to have some exceptional olive oil from a friend’s olive trees and that really touched it off. Can’t wait to use this in a fun recipe. Easiest tomato sauce recipe ever.
I’ve made this twice now, and absolutely love the flavor. It is now my go to for tomato sauce.
I finally got the chance to make this and loved it! Got San Marzano tomatoes from the Farmer’s Market, and made your meatballs to go with it. I grow my own garlic, so used that. It came out so good, went back to the Farmer’s Market and bought a 25 lb box of Roma tomatoes and roasted them on the Smoker. Crazy good! Thanks for the recipe!
Wow! Have fun with that!
Made this today, it was so easy and the house smelled amazing!!! Thank you Carolyn!
I have an abundance of tomatoes from my 1 plant and I was so excited to finally make this! It is so easy and so delicious!
could this be used as a base for tomato soup?
Please search my site for the soup, I already have one.
Just made this today, wonderful! Thank you!
Same question as Chris, 3 total (cups?) thanks! Sounds delicious! Yes, tomatoes are coming in fast!
yes, cups 🙂
I love all your of your recipes, but I have a question about your instructions here. You say “Add just enough of the liquid in the pan to measure out 3 total (tomatoes and juice).” What is the 3 total? Thank you!
cups
This is exactly what I need! I’m heading to the farm stand this afternoon. Thanks!
before roasting tomatoes should they be peeled?
Please read the blog post.
I am a canner. Is this recipe able to be canned? I saw the olive oil in it, so not sure.
Would love a recipe for canning jams if possible.
My freezer is full of other freezable food!
I am sure it can be but you may need some additional acid to offset spoilage. I would google it if I were you.
I typically add 1/4 tsp citric acid per pint when I’m canning anything tomato. Some say add lemon juice, but I don’t like the extra lemon taste.
Thank you! That helps a lot!
Thanks Beth…that is exactly what I use in my tomatoes, too! How long do you process them in quarts, and in WB or Pressure? TIA!
Oooooo…. I can’t wait to try this. It’s the perfect season for tomatoes so this is perfect. I wonder if I lessened the liquid if I’d get more of a paste which is also something I use a lot.
Probably! You could even cook it down further after blending.