Give your next pasta dinner an upgrade with smoky, sweet, and slightly spicy Grilled Onion and Pepper Pasta Sauce. 

Overhead shot of bowl with spaghetti and pasta sauce with fork and spoon

If you haven’t finished harvesting your tomatoes and peppers yet, it’s probably time! We think of these as summer vegetables (or, fruits, if we want to be technical about it), but sometimes it’s not until the beginning of fall when everything starts to ripen. Other times, our plants seem to get a second wind in September and suddenly they’re heavy with unripe fruit again. All this is to say that if you find yourself with a lot of tomatoes and some peppers on your hands, this Grilled Onion and Pepper Pasta Sauce is the perfect way to use it.

There’s so much flavor in every jar of this sauce, you’re going to wonder how you ever ate pasta without it. A lot of that flavor comes from the grilling, which gives the vegetables that signature smoky flavor. (And because you can’t ever have enough smokiness, I added smoked paprika too.) The Walla Walla onions add sweetness, and the poblanos, Anaheim peppers, and jalapeños bring a little heat to warm you up on a chilly fall evening. 

Because this recipe can be canned, you’ll be able to enjoy a little taste of summer (or late fall) all year long!

Two bowls of spaghetti with Grilled Pepper and Onion Pasta Sauce with jar of sauce in background

What You’ll Need

Of course, if you don’t have a garden, no worries—now is a great time of year to hit up your local farmstead or farmers market and find a bounty of tomatoes for sale alongside the apples and winter squash. Here’s what you’ll need to make my Grilled Onion and Pepper Pasta Sauce:

  • Sweet Onions – Vidalia, Walla Walla, or any onion labeled as sweet will do.
  • Poblano or Anaheim Peppers – Both of these add mild heat to your pasta sauce.
  • Red Bell Peppers – Orange or yellow could be used, too.
  • Jalapeños – These are optional; use them if you want to add more heat.
  • Ripe Tomatoes – Pasta sauce is a great way to use all your unattractive tomatoes that aren’t destined for a perfect caprese salad or tomato tart. Cracks, odd shapes, it’s all good as long as the tomato isn’t spoiled.
  • Brown Sugar – You always need to add a bit of sugar to a tomato sauce, and the caramel notes in brown sugar complement the grilled veggies.
  • Cider Vinegar
  • Kosher Salt
  • Smoked Paprika – Make sure the paprika you buy is smoked—standard paprika or hot paprika isn’t the same!
  • Garlic – I minced the garlic, but you can cut it into slices if you prefer.
  • Fresh Rosemary – Basil or oregano work, too, if you happen to have those on hand.
  • Lemon Juice

How to Peel Tomatoes

Use a sharp paring knife to remove the stems from the tomatoes, then slice an X through the skin on the bottom. Drop the tomatoes into a pot of boiling water for about 30 seconds, or when you start to see the skin curling up and peeling where you cut the X. Transfer the tomatoes to a pot of ice water for 5 minutes, then drain them and peel the skin off. It should come off easily!

Closeup of bowl filled with spaghetti topped with pasta sauce and garnished with fresh basil sprigs

How to Make Grilled Onion and Pepper Pasta Sauce

Homemade pasta sauce takes some time, but it’s absolutely worth it. You’ll save money making your own and let’s be real: you can’t get pasta sauce that’s filled with grilled veggies at the grocery store!

Grill the vegetables. Grill the onions and peppers on a gas or charcoal grill until they’re tender and blackened in spots. Immediately after removing them from the grill, wrap them tightly in foil or place them in a large zip-top bag. This lets them steam and loosens the pepper skins. 

Prepare the vegetables for the sauce. When the veggies are cool, place them on a cutting board and peel off the skin, then pull off the stems and discard the seeds. Chop the peppers and onions.

Start cooking the tomatoes. Put all the tomatoes in a large Dutch oven and stir in the brown sugar, vinegar, salt, and paprika. Bring to a boil and let the tomatoes continue to boil for about 50 minutes, or until they have cooked down.

Finish the sauce. Stir in the grilled vegetables and garlic, and continue to cook for another 30 or 40 minutes, or until the sauce reaches the consistency you’d like. Remove from heat. At this point, you can leave the sauce as-is, or use an immersion blender to make it smoother. Add the rosemary.

Spooning homemade pasta sauce over spaghetti in bowl

How to Can Homemade Pasta Sauce

To process this Grilled Onion and Pepper Pasta Sauce for long term storage, pour a tablespoon of lemon juice into the bottoms of hot canning jars. Ladle the hot pasta sauce into the jars over the lemon juice, leaving a half inch of headspace. Wipe the rims of the jars clean, and place the lids and bands on, sealing to finger tight.

Can This Recipe Be Frozen?

Yes, if you don’t have the equipment (or desire) to can, you can definitely freeze this sauce instead. I recommend freezing it in zip-top freezer bags because the air can be pressed out to prevent freezer burn and they can be frozen flat. Let the sauce thaw in the fridge, then empty it into a saucepan or microwave-safe container for heating.

Serving Suggestions

You can’t go wrong tossing your favorite pasta with Grilled Onion and Pepper Pasta Sauce, but here are some more ways to use it:

Two bowls of spaghetti topped with pasta sauce, shredded parmesan, and basil
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Overhead shot of bowl with spaghetti and pasta sauce with fork and spoon

Grilled Onion and Pepper Pasta Sauce

  • Author: Megan Keno
  • Prep Time: 40 minutes
  • Cook Time: 1 hour 25 minutes
  • Total Time: 2 hours 5 minutes
  • Yield: 6 pint jars 1x
  • Category: Canning
  • Method: Stovetop
  • Cuisine: American


This homemade pasta sauce is full of smoky flavors and just a bit of heat!


Units Scale
  • 2 Sweet or Walla Walla Onions, Cut into 3/4” slices
  • 3 Poblano or Anaheim Peppers
  • 3 Red Bell Peppers
  • 24 Jalapenos, if desired
  • 12 pounds Ripe Tomatoes, peeled and seeded
  • 1/4 cup Brown Sugar
  • 3 Tbsp Cider Vinegar
  • 2 Tbsp Kosher Salt
  • 1 Tbsp Smoked Paprika
  • 12 Cloves Garlic, minced
  • 1/4 cup Fresh Rosemary, minced
  • 6 Tbsp Lemon Juice


On a gas or charcoal grill over medium-high heat, grill onions, and all peppers until blackened and onions are tender and browned. Remove them from the grill, and place them in foil, or plastic Ziplock bags until they are cool enough to handle. When cool, remove the stems and seeds and blackened skin from the peppers and discard. Chop the peppers and onions and set aside. 

Place cut and seeded tomatoes into a 6- or 7-quart Dutch Oven. Stir in brown sugar, vinegar, salt and paprika to the pot. Bring the mixture to a boil, allowing to cook down for about 50 minutes, stirring frequently. Stir in the grilled onions, grilled peppers, and garlic. Continue to cook for 30-40 minutes, until it reaches desired consistency. To break down the sauce, blend the sauce to your desired consistency with an immersion blender. Leave it with some chunks of grilled vegetables. Remove and stir in the rosemary.

To process for long term storage, pour one tablespoon of lemon juice into the bottom of hot canning jars. Ladle the hot pasta sauce into the jars on top of the lemon juice, leaving ½” headspace in the jars. Wipe the rims of the jars clean, and place lids and bands on sealing to finger tight. 

Process the jars in a boiling water canner for 35 minutes, starting the timer when the water reaches boiling. Remove from the canner and cool on a wire rack to seal and cool completely. 

Keywords: homemade pasta sauce, spaghetti sauce recipe, canning spaghetti sauce