Keto Marinara Sauce Recipe - Slow Cooker, Instant Pot, Stovetop

Published: Oct 3, 2019 by Wendy Polisi Modified: Mar 8, 2022 · 1243 words. · About 7 minutes to read this article.

This Keto Marinara Sauce recipe is one you will turn to again and again. It is perfectly balanced with sweetness and acidity. Sautéing the onions first will bring out the sweetness, making it unnecessary to add sugar to the sauce. Sure, you can buy marinara, but homemade tastes so much better. (Plus - it is always great to control what is going into what you are eating!) The hands-on time is minimal here, and you will be richly rewarded for your efforts. I especially like this with my Keto Chicken Parmesan. Try it once and, like me, you'll be addicted!

Overhead photo of Keto Marinara in a cast iron skillet garnished with parsley sitting on a white background.

The Whole Family Will Love This Keto Marinara Sauce!

Last Updated: 3 Oct 2019

One of the hardest things about being on a low carb or keto diet is having to cook one meal for myself and another for my kids.

I try to avoid this as much as possible and find a special joy when I create basic recipes - like this Keto Marinara - that the whole family will love.

I know a lot of people resist the idea of making things that they can easily buy, and I get it.

But I promise - this is so simple to throw together on the weekend, and it tastes A-MA-ZING!

This recipe makes a chunky marinara sauce. If you want it smoother, process it in the blender until it reaches the desired consistency. (This is what I often do - that way the kids can use it for pizza and meatballs.)

I've used this to make Keto Manicotti (coming soon), and I must say it was out of this world.

Photo of a keto quickstart guide with the description of the guide on the right.

As an Amazon Associate I Earn From Qualified Sales

How to Make Keto Marinara Sauce

Step 1: Heat olive oil and butter in a stock pot.

Step 2: Add onion and cook for 4 minutes. Add garlic and cook for 1 minute longer.

Photo of oil, chopped onion, and garlic cooking in a skillet.

Step 3: Stir in tomatoes, Italian seasoning, salt, pepper and crushed pepper flakes.

Step 4: Bring to a boil. Reduce the heat to a simmer and cook for 40 minutes.

Frequently Asked Questions

What are the ingredients for Keto Marinara Sauce?

Unsalted butter
Extra-virgin olive oil
Onion
Garlic
Canned whole peeled tomatoes
Italian seasoning
Sea salt
Black pepper
Crushed red pepper flakes

Is marinara and tomato sauce OK on a keto diet?

Tomatoes and tomato sauce, in moderation, is ok on a Keto diet. However, prepared marinara, pizza sauce, and other red sauces often have added sugars in them. For this reason, it is important that you read labels if you are going to buy tomato sauce and marinara.

As an Amazon Associate, I earn From Qualifying Sales

What is the best brand of canned tomatoes to use on keto?

It is essential always to read labels when choosing tomatoes. Many brands have added sugars, which is something you should avoid. (Especially since tomatoes already have added sugars.) Many brands will work. My favorite is Muir Glen Organic.

How many carbs are in homemade marinara sauce?

The carbohydrate count will vary by recipe, but this sugar-free marinara has just 4 net carbs per serving.

Can I use crushed tomatoes instead of whole tomatoes?

I prefer whole tomatoes because the flavor is so much better, but you can absolutely use crushed tomatoes if you prefer.

How long does this recipe keep in the refrigerator?

This recipe will keep for three to four days in the refrigerator.

Can this be frozen?

This recipe can be frozen for up to three months.

Photo of Low Carb Marinara in a large cash iron skillet with a wooden spoon in it garnished with parsley.

Variations for This Recipe:

You can use 3 ½ pounds of fresh ripe tomatoes in place of the canned tomatoes.
If desired, stir in fresh basil and/or oregano in the last 10 minutes of cooking.
If you are low carb and not keto, a grated carrot added in when you add the onion adds a nice hint of sweetness.
Stir in 3 ounces of Parmesan cheese at the end.
If you find the sauce to be too acidic, you can add a pinch of baking soda.
For a super-creamy tomato sauce, add 2 tablespoons of butter to it at the end.

Slow Cooker Keto Marinara Sauce

Complete steps one and two on the saute' function of your slow cooker, or on the stovetop.
Add all the ingredients to your slow cooker, and cook on low for 8 hours.

Instant Pot Keto Marinara Sauce

Turn your Instant Pot to saute, and add the butter and olive oil to the pot.
When the butter melts, add onion and cook for 4 minutes. Add garlic and cook for another minute.
Stir in tomatoes, Italian seasoning, salt, pepper, and crushed pepper flakes.
Close the lid, and make sure it is set to seal.
Cook on high pressure for 10 minutes.
Release the pressure using the quick-release method.
Carefully unlock and remove the lid.

If You Like This Low Carb Marinara You May Also Like:

This Keto Chicken Parmesan is simple enough for a weeknight, but fancy enough for company!
This Keto Meatloaf is pure comfort food!
Most often I make this Keto Eggplant Lasagna recipe with a meat sauce, but for for a vegetarian option this marinara works fabulously.