Roasted Tomato Marinara Sauce (an Easy Low-Carb Pasta Sauce Recipe!)

Low-carb pasta sauce on Kaizen lupin flour pasta in a white dish.

POV: you have your box of Kaizen Lupini Pasta and now you're in search of the perfect low-carb pasta sauce recipe (and who can blame you, we all need a go-to red sauce in our lives!). Enter this roasted tomato marinara sauce! It's a simple keto recipe with bold Italian flavors.

Whether you're looking for a low carb marinara sauce for those zucchini noodles or for dipping or topping any of our high-protein, plant-based lupini bean pastas, this one will serve you well! 

Serve it with fresh burrata, Parmesan cheese or even meatballs for a delicious, comfort food meal that packs a flavor and nutrition punch, yet conveniently remains low in net carbs and sugar free.

About Kaizen Pasta

That's the beauty of our lupini pasta compared to traditional pasta. It is plant based, gluten and grain free, low carb and keto diet friendly.

Each serving packs a whopping 20 grams of protein, 15 grams of fiber and only 6 grams net carbs.

Kaizen offers more than a bland pasta alternative - we're all about enjoying our favorite foods while nutritiously fueling our bodies. The ultimate #pastagoals.

The Saucy Details

What makes this the perfect low-carb marinara sauce?! Simple ingredients shine and there is zero added sugar in this easy recipe.

Roasting fresh tomatoes adds a depth of flavor that creates a delicious, low-carb base for this homemade sauce. The ripe tomatoes roast over a high heat and become juicy and slightly caramelized, rich and concentrated.

You'll also love the versatility of this low-carb pasta sauce recipe. Stir red pepper flakes or a dash of cayenne into the sauce for a touch of heat. 

If you prefer a meat sauce, you can easily add ground beef or Italian sausage (or both!). 

Fold in your favorite freshly-grated cheese or add it as a garnish for a delicious, cheesy finish. There's no wrong way to enjoy this great recipe!

A Low-Carb Pasta Sauce Recipe

The sauce comes together with very little effort and it has so much flavor!

The main ingredient here is, of course, the roasted tomatoes. And that's what sets our low-carb marinara sauce apart from store-bought sauces.

This sauce is a great way to maximize peak tomato season. Keep in mind that the quality of your fresh tomatoes will really make a difference!

While we use dried oregano and dried thyme in this keto sauce for ease, you can swap in Italian seasoning or fresh herbs (simple double the amount the recipe calls for if you're opting to use fresh!).

Roasted Tomato Marinara (Low-carb Pasta Sauce)

Yield: 2-3 servings


  • 10-12 tomatoes, cut in half
  • 3 tablespoons extra virgin olive oil, divided
  • ⅓ large red onion, diced
  • 4 garlic cloves, grated
  • Pinch of salt and black pepper
  • 1-½ teaspoons dried oregano
  • 1-½ teaspoons dried thyme
  • 12 ounces canned tomato sauce
  • 1 tablespoon balsamic vinegar
  • 1 teaspoon ground paprika
  • 8 ounce package Kaizen lupini bean pasta, any variety (pictured is our Ziti)
  • fresh burrata cheese or Parmesan cheese (optional)
  • Fresh basil, olive oil and red chili flakes (optional garnish)

  1. Preheat the oven to 425°F. Place the tomato halves on a parchment-lined baking sheet. Drizzle with about 2 tablespoons of olive oil. Roast for 30-40 minutes or until the skins can easily lift and peel away from the tomato flesh. Let the roasted tomatoes cool until they're cool enough to handle, about 15-20 minutes. Finely chop them and transfer to a bowl, pan juices and all. Note: finely chop the tomatoes for a smoother sauce. For a chunky sauce, roughly chop the tomatoes.
  2. Add the remaining 1 tablespoon olive oil to a pan over medium heat. When the oil glistens, add the red onion, fresh garlic and cook for a few minutes. Mix in the salt, pepper, oregano and thyme.
  3. Add the roasted tomatoes (and juices) to the pan along with the tomato sauce. Stir in the balsamic vinegar and paprika.
  4. Mix and cook for about 20 minutes to let the sauce reduce. Taste and adjust the seasonings, if needed.
  5. Heat a large pot of water with 1 teaspoon salt on the stovetop until it is boiling. Pour in the Kaizen lupini pasta and cook for 5-8 minutes. Reserve ½ cup of the pasta water and drain the rest.
  6. Add the drained pasta to the sauce along with the ½ cup pasta water.
  7. Serve the pasta with fresh cheeses like burrata or parmesan and finely shredded basil, a drizzle of extra olive oil and red chili flakes, if desired.

Time-saving tip: Roast the tomatoes the day before to cut prep time down to a minimum when you're ready to make the sauce.

Frequently Asked Questions

How long will low-carb marinara sauce keep?

Store leftovers in an airtight container for up to one week. You can also freeze the sauce for 2-3 months in a freezer-safe storage container or freezer bag.

What can I use instead of sugar in pasta sauce?

Sugar is typically used in marinara sauces to mellow out the acidity of the tomatoes. Since our low-carb pasta sauce recipe calls for roasted tomatoes, you'll find that they have a sweeter, more complex flavor than fresh tomatoes which can sometimes taste a bit acidic. If you find that the sauce needs to mellow slightly, try adding a pinch of baking soda. Just a small amount of this alkaline will help balance out the acidity in the sauce. A tiny bit of a keto-friendly sweetener will also do the trick!

What is the best way to store the sauce?

Store leftovers in an airtight container for up to one week. You can also freeze the sauce for 2-3 months in a freezer-safe storage container or freezer bag.

More Recipes to Try

About Lupini

New to lupini pasta? Learn more about this incredible superfood!

Let's Connect!

What are your favorite ways to enjoy this low-carb pasta sauce?

Snap a photo and tag us on Instagram @kaizenfoodcompany- we love to see how you flex your Kaizen creations with all of our low-carb pastas!