Vegetarian Slow Cooker Spaghetti Sauce

Name: Vegetarian Slow Cooker Spaghetti Sauce
Prep time: 10 min
Total time: 370 min
Ingredients: 3 bell peppers (yellow, red and green bell pepper, cut into 1-inch pieces.); 1 small yellow onion (diced); 29 oz. diced tomatoes ((two 14.5-oz. cans)); 6 oz. tomato paste; 8 oz. tomato sauce; 1 Tbsp. Italian seasoning; 2 minced garlic cloves ((about one tablespoon)); 1/2 tsp. sea salt; 1/4 tsp. red pepper flakes (omit if you don't want any heat); 1 Tbsp. sugar

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This recipe for vegetarian slow cooker spaghetti sauce will leave your family happy and satisfied. You can make this easy dish for any occasion, as it tastes great with any noodles or rice and is easy to make for a crowd.

This recipe is excellent for meatless Monday! Try my Slow Cooker Spaghetti Sauce recipe if you need a meaty sauce.

pasta sauce with bell peppers in slow cooker (no meat)

Why this recipe works

It’s perfect to use up those cans of tomatoes you have sitting around in the pantry, so go ahead and dig them out! This recipe requires less than 10 minutes of prep time before going into the crockpot to cook all day long. This recipe is similar to the Italian recipe Peperonata, which is filled with sweet bell peppers.

When you get home from work, the only thing left is to make your favorite pasta on the stovetop, then serve over cooked pasta.

ingredients for vegetarian spaghetti sauce on table

Recipe Ingredients

Vegetables – Three bell peppers, onion and garlic.
Canned Tomatoes – Tomato paste, tomato sauce and diced tomatoes will make a perfect texture for the base of your sauce.
Seasonings – Italian seasoning, salt, pepper and red pepper flakes.
Sugar – This makes all the difference, we aren’t adding much but just enough to take the acidity from the sauce. You’d be surprised to know that almost every store bought sauce has a touch of sugar.

Step-by-Step Directions

Step One – Add everything to the crockpot.

Step Two – Stir. Cook on HIGH for 4 hours or on low for 6 hours. Serve and enjoy!

spoon in bell pepper pasta sauce in slow cooker

How to serve vegetarian spaghetti sauce

You can serve slow cooker three pepper pasta sauce with cooked noodles of your choice, or even rice to pair the meal with.
This dish is also great for dipping bread and garlic toast in, or even topping a sandwich!
Serve with a green salad if desired.

overhead shot of vegetarian sauce on spaghetti noodles

Recipe FAQs and Variations

How to store:

You can store it in the fridge for up to 3 days after making the recipe. If you are looking for a more extended storage option, transfer leftovers into freezer-safe containers and freeze for up to three months.

Why sugar in pasta sauce?

Adding sugar to a pasta sauce may sound odd, but it offers a layer of complexity that you wouldn’t get otherwise. With the right amount of sweetness and acidity, this dish is sure to be a hit with your family! Just remember only to use one tablespoon of sugar!

What is the best way to reheat spaghetti sauce?

Be sure to thaw your sauce in the fridge if you have taken it out of the freezer. The best way to reheat is in a small saucepan over medium heat on the stovetop. Or you can heat in the microwave, be sure to cover your bowl or plate with a paper towel, for it will splatter everywhere.

Can I add meat or soy crumbles?

Yes! Add one pound of cooked, and crumbled ground beef or 1-2 cups of soy crumbles for a meaty pasta sauce.

What can I use instead of Italian seasoning?

If you don’t have Italian seasoning, you can use this combination: One teaspoon dried basil, one teaspoon dried oregano, 3/4 teaspoon dried thyme, and 1/4 teaspoon dried rosemary. Or any blend of those spices you prefer, though rosemary can be very strong, so use it sparingly.

Can I add wine?

Yes! Add 1/4 cup of red wine (such as pinot noir or Cabernet Savignon) to this recipe at the beginning of the cooking time. Though, be sure to tell your guests that there is wine in the sauce for the alcohol doesn’t cook out completely.

bowl of noodles with vegetarian sauce and parmesan

Pasta with peppers and onions is so flavorful, and the slow cooker makes it easy to whip up a quick meal! You no longer have to spend all day in the kitchen, so sit down with your family and enjoy this Italian favorite.

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