Get the flavor of a thick, hearty, and rich keto tomato sauce in a fraction of the time with this Oven Roasted Tomato Sauce. Hungry? Read on, and I, Chef Jenn, will show you all my tips and tricks to make this the best keto tomato sauce out there!

This dish has FOUR ingredients, if you don’t count the salt and pepper, and coming in at just 3 NET CARBS per generous 1/3 cup serving, this is one Keto-friendly dish you can really dig into.
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There’s one surprise ingredient in this simple sauce. Are you ready for it?
Butter.
Yup, butter. Good old fashioned salted butter. The butter does something to the sauce as it cooks, imparting a richness, creaminess, and oh-so goodness that you can only get from cooking tomatoes on the stove-top all day.
Add some garlic, the requisite butter, and cook this sauce in a hot oven for about an hour. It’ll thicken up and when done, will have unbelievable flavor.
How To Make Keto Marinara SAuce
You want to start with a deep, oven-safe dish. This recipe can get kind of splattery, so start with a deep Pyrex or casserole dish. I LOVE these stackable Pyrex dishes, and they have lids so no wasted plastic wrap.
Use diced tomatoes or whole tomatoes – it doesn’t really matter. Just break up the tomatoes with your very clean hands, or use a potato masher to smash them up.
Add peeled garlic, salted butter, and that’s it! Into the oven it goes, and you can stir it halfway through to make sure it cooks evenly.
Be careful taking the dish out of the oven – that tomato sauce is hot and you don’t want the molten sauce to get on you.
Does Oven-Roasted Tomato SAuce Freeze
I always make a double batch of this sauce and freeze the rest for another meal. You can freeze it in single-serving size, or freeze it in a larger quantity for family dinners.
To freeze this keto marinara sauce recipe, make sure it is fully chilled. Put it into freezer-safe plastic bags and squeeze out the excess air. Then, freeze it for up to three months.
To use, fully thaw the keto tomato sauce, and use it in your favorite recipes!
Where To USe This Tomato SAuce?
You can use this keto Oven Roasted Tomato Sauce in a variety of dishes, including my family’s favorite Sausage Parmigiana. Simply freeze it in two or three cup batches, and you’re good to go!
You can even add some herbs and spices to this basic recipe, jazzing it however you like. Use it over Zucchini Noodles, or in any of your favorite dishes.
Pizza SAuce?
Another great use of this keto tomato sauce recipe is to turn it into pizza sauce. To the basic recipe, add 1 tsp dried oregano, 1 tsp dried basil, and 1 tsp garlic powder. Mix well and use like any pizza sauce.
SAve Money!
Tomato sauce always makes Keto dieters a bit nervous, because of hidden sugars. But this tasty version coaxes big, balanced flavors from the tomatoes without the addition of starch or sugar, both of which often show up in commercial tomato sauces.
And, it is much more affordable than buying keto jarred sauces. Plus, it is so easy to make, just buy the canned diced tomatoes on sale, and you can have luscious tomato sauce for hardly any money.
If you’re a tomato lover, you might also love this recipe for easy keto ketchup!
Chef’s tips
- Watch the ingredients on your canned tomatoes. Make sure there’s no added sugar.
- Use salt-free canned tomatoes to control the sodium.
- Jazz up the flavor with your favorite herbs and spices.
- Add a pinch of red pepper flakes to make it spicier!
- You can use organic canned tomatoes or regular store brand. Either is fine.
Click on the carousel below for step-by-step pictures, or just follow along with the recipe, and in no time, you’ll have a batch of hot and tasty keto-friendly tomato sauce ready in no time!
Also Try…
Good quality tomatoes for Keto Oven Roasted Tomato Sauce. Use a potato masher to break up the big tomatoes. Still chunky after being broken up by the potato masher. Butter, garlic, and voila, it’s ready for the oven!
Keto Oven-Roasted Tomato Sauce
Ingredients
- 56 ounces canned tomatoes (2 28-ounce cans of whole, crushed, or diced)
- 1/2 cup butter
- 6 cloves garlic smashed
- 1 tsp salt or to taste
- 1/2 tsp pepper
Instructions
- Empty the two 28-ounce cans of tomatoes into an oven-safe shallow dish. I used a 13 x 11 pyrex dish for this dish. If the tomatoes are whole, crush them with your hands or a potato masher.
- Dot the top of the tomatoes with butter. Yes, butter! Butter adds unbelievable richness and flavor to this sauce. Add the garlic.
- Bake at 425-F for about an hour, stirring once or twice during the cooking time.
- Remove from the heat and using the back of a fork or a potato masher, mash up the remaining chunks of tomato and garlic. Season with salt and pepper, and use in your favorite dish.
Nutrition
A Note on Nutritional Information
Nutritional information for this recipe is provided as a courtesy and is calculated based on available online ingredient information. It is only an approximate value. The accuracy of the nutritional information for any recipe on this site cannot be guaranteed. Erythritol carbs (sugar substitutes) are not included in the carbohydrate counts as they have been shown not to impact blood sugar, and they have zero calories and zero carbs. Net carbs are the total carbs minus fiber.
Oh my gosh, this is so good!!! I made it tonight to have ready for a meal this upcoming week (although I haven’t decided exactly what yet) and immediately after tasting it my husband said, “oh, this is absolutely delicious! We need to use this ASAP!” 😁
Thank you for sharing!!
This oven roasted sauce sounds wonderful. Will be trying this. Thank you
I’ve made this in my insta pot (14 min, natural release) and it tasted like I cooked it for 3 hours. I had doubled the recipe, cooled the portion that I wanted to freeze before pouring into freezer bags. Lay flat to freeze. Awesome sauce!
this sauce is delicious. I have many complements on it!!!!
I’m so glad you like it, and thanks for stopping by to tell me! ~Jenn