• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer
Sula and Spice
  • Recipes
  • Tips and Tricks
  • About Sula
  • Privacy Policy
    • Facebook
    • Instagram
    • Pinterest
menu icon
go to homepage
subscribe
search icon
Homepage link
  • Recipes
  • Tips and Tricks
  • About Sula
  • Privacy Policy
    • Facebook
    • Instagram
    • Pinterest
    • YouTube
  • ×
    Home » Main Dishes » Vegetarian Spaghetti Squash Casserole

    Vegetarian Spaghetti Squash Casserole

    Published: Jan 22, 2020 · Modified: Jan 15, 2023 by Sula · This post may contain affiliate links · 13 Comments

    Jump to Recipe

    Many times when I make spaghetti squash, I use only half of it for the intended dish. Ratatouille, for example. Somehow we manage to eat an entire batch of ratatouille and only use half a spaghetti squash to go with it. Half a cooked squash sitting in the refrigerator sticks out like a sore thumb. So, I began experimenting. This spaghetti squash casserole is one of the happy results.

    Ingredients needed

    ingredients are cooked squash, zucchini, mushrooms and canned tomatoes

    Actually, the combination of ingredients was a result of cleaning out the fridge. Half a box of mushrooms, one zucchini and one green onion? Great combo!

    How to make this vegetarian spaghetti squash casserole

    The magic is in the sauce. Heat some oil in a small saucepan and cook the mushrooms and zucchini for 3-5 minutes until the mushrooms start to release their juices. Then add the onion to cook for a minute before adding a can of diced tomatoes, some Italian seasoning and garlic powder. This mixture is simmered for 5-7 minutes to develop the flavors then removed from the heat to cool slightly.

    Shred the cooked and cooled squash into a mixing bowl and pour in the tomato sauce. Mix together, then add Parmesan cheese.

    ingredients mixed in white casserole dish

    Get out a 1 ½ quart casserole dish and pour the squash mixture into the dish.

    Bake, uncovered, for 30 minutes.

    baked spaghetti squash casserole right out of the oven

    Remove from oven and allow to rest for at least 15 minutes before serving.

    vegetarian spaghetti squash casserole after resting, finished

    In this time the mixture will cool slightly and absorb some of the liquid in the dish making the squash strands much more moist and flavorful.

    This dish is a tasty variation on spaghetti squash with an array of tastes and textures. The mushrooms provide a little extra heartiness to this plant-based dish. It works well as a vegetarian main dish, or a side with something else.

    Variation ideas

    Can you try other veggies? Sure! I think broccoli would work well, I just haven’t tried that variation (yet). Cubed sweet potato has potential as well. Many possibilities with this one!

    vegetarian spaghetti squash casserole in one red and one yellow bowl

    If you’re trying to increase the veggies in your diet, this low carb and vegetarian spaghetti squash casserole is a great solution!

    📖 Recipe

    vegetarian spaghetti squash casserole in one red and one yellow bowl
    5 from 41 votes
    Print Pin it!
    Prevent your screen from going dark

    Vegetarian Spaghetti Squash Casserole

    A simple low carb keto friendly side dish using your extra spaghetti squash!
    Prep Time10 minutes mins
    Cook Time40 minutes mins
    Resting time15 minutes mins
    Course: Side Dish
    Cuisine: American
    Servings: 4
    Calories: 184kcal
    Author: Sula

    Ingredients

    • ½ spaghetti squash cooked and cooled
    • 1 TB olive oil
    • 14 oz can diced tomatoes undrained
    • 1 small zucchini chopped
    • 4 oz mushrooms chopped
    • 1 green onion sliced thin
    • 1 teaspoon Italian seasoning
    • ½ teaspoon garlic powder
    • ¾ cup shredded Parmesan cheese

    Instructions

    • In a small saucepan, heat oil and add mushrooms and zucchini. Cook for 3-5 minutes until mushrooms begin to release their juices. Add onion and cook for one minute, then add the diced tomatoes. Add garlic powder and Italian seasoning and stir.
    • Simmer for 5-7 minutes. Remove from heat.
    • Shred spaghetti squash into a medium bowl, pour in tomato sauce and stir. Add Parmesan cheese and mix to combine.
    • Transfer the spaghetti squash mixture into a 1 ½ quart casserole dish.
    • Bake, uncovered, for 30 minutes at 350F.
    • Remove from oven and allow to rest for 15 minutes before serving.

    Nutrition

    Calories: 184kcal | Carbohydrates: 16g | Protein: 10g | Fat: 10g | Saturated Fat: 4g | Cholesterol: 17mg | Sodium: 455mg | Potassium: 558mg | Fiber: 4g | Sugar: 8g | Vitamin A: 551IU | Vitamin C: 22mg | Calcium: 282mg | Iron: 2mg

    Nutrition values are estimates only, using online calculators. Please verify using your own data.

    Pin for vegetarian spaghetti squash casserole

    Looking for more zucchini recipes? Here are a few:

    • Zucchini and beef casserole
    • Zucchini corn fritters
    • Grilled zucchini
    • Summer squash -microwave

    More options for spaghetti squash:

    • Grilled spaghetti squash
    • Mediterranean spaghetti squash salad
    « Avocado Fries
    Keto Strawberry Fat Bombs »

    Sharing is caring!

    • Facebook
    • Yummly
    • Flipboard

    Filed Under: Main Dishes, Vegetarian

    Reader Interactions

    Comments

    1. Amanda Wren-Grimwood

      September 17, 2020 at 8:08 am

      5 stars
      We are trying to eat plant based a few times a week and this is a great addition to our meal plans!

      Reply
      • Sula

        September 17, 2020 at 11:35 am

        Oh yes, this works so well as either a main or side dish!

        Reply
    2. Ashley

      September 17, 2020 at 7:58 am

      5 stars
      What a great way to use up fridge veggies!! Definitely trying this one soon!

      Reply
      • Sula

        September 17, 2020 at 8:00 am

        Yes it's very handy for fridge veggies LOL.

        Reply
    3. Bless my food by payal

      September 17, 2020 at 7:53 am

      5 stars
      That looks absolutely stunning and delicious.

      Reply
      • Sula

        September 17, 2020 at 8:02 am

        Thanks, I hope you try it soon!

        Reply
    4. Lauren Vavala

      September 17, 2020 at 7:46 am

      5 stars
      I just love this vegetarian spaghetti squash casserole recipe! It's hearty and filling - perfect for our Meatless Mondays.

      Reply
      • Sula

        September 17, 2020 at 8:02 am

        Yes, I love it for meatless Mondays too!

        Reply
    5. Jillian

      September 17, 2020 at 7:44 am

      5 stars
      I was just wondering what to do with some extra zuchinni that I have in my fridge. This is great!

      Reply
      • Sula

        September 17, 2020 at 8:03 am

        So glad you like it!

        Reply
    6. Big Trouble

      January 24, 2020 at 8:21 am

      5 stars
      Oh wow, broccoli would be AMAZING in this, too! Yummy!!! Do you think it would still be delicious without the parmesan? I suppose I could try vegan parm. Looks hearty AND healthy! Nice job, Sula!

      Reply
      • Sula

        February 04, 2020 at 11:13 am

        It's definitely worth a try. Depending upon how much flavor the vegan cheese has, it might be worth increasing the spices. Maybe?

        Reply
      • Sula

        February 04, 2020 at 11:15 am

        Oh, and by the way, I did try it recently with broccoli and LOVED it!

        Reply

    Leave a Reply Cancel reply

    Your email address will not be published. Required fields are marked *

    Recipe Rating




    Primary Sidebar

    Follow along!

    • Pinterest
    • Instagram
    • Facebook
    • YouTube

    Sula and Spice is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. More information on affiliate links can be found here

    Welcome!

    Sula

    Welcome, I am so glad you are here! I once told someone that my favorite reading materials were cookbooks and menus. He didn’t understand. But since you are here, I’ll bet you get it…. at least a little, right?

    Recent Posts

    • Halloween Skull Caprese Skewers
    • Spider Web Black Bean Dip
    • Brownie Mix Crinkle Cookies
    • Old Fashioned Pumpkin Cookies
    • Old Fashioned Fresh Apple Cake

    Subscribe to blog updates

    Enter your email address to subscribe to this blog and receive periodic emails with updates.

    Please wait...

    Thank you for subscribing!

    Archives

    Footer

    About Sula and Spice

    • Facebook
    • Instagram
    • Pinterest

    Welcome, I am so glad you are here!

    I once told someone that my favorite reading materials were cookbooks and menus. He didn’t understand. But since you are here, I’ll bet you get it…. at least a little, right?

    My Favorites

    Halloween skull Caprese skewers.
    Spider web black bean dip for Halloween.
    Brownie mix crinkle cookies cooling on a wire rack.

    Copyright © 2023 · Sula and Spice