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
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.
Get out a 1 ½ quart casserole dish and pour the squash mixture into the dish.
Bake, uncovered, for 30 minutes.
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Remove from oven and allow to rest for at least 15 minutes before serving.
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!
If you’re trying to increase the veggies in your diet, this low carb and vegetarian spaghetti squash casserole is a great solution!
📖 Recipe
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Vegetarian Spaghetti Squash Casserole
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
Nutrition values are estimates only, using online calculators. Please verify using your own data.
Looking for more zucchini recipes? Here are a few:
More options for spaghetti squash:
Amanda Wren-Grimwood
We are trying to eat plant based a few times a week and this is a great addition to our meal plans!
Sula
Oh yes, this works so well as either a main or side dish!
Ashley
What a great way to use up fridge veggies!! Definitely trying this one soon!
Sula
Yes it's very handy for fridge veggies LOL.
Bless my food by payal
That looks absolutely stunning and delicious.
Sula
Thanks, I hope you try it soon!
Lauren Vavala
I just love this vegetarian spaghetti squash casserole recipe! It's hearty and filling - perfect for our Meatless Mondays.
Sula
Yes, I love it for meatless Mondays too!
Jillian
I was just wondering what to do with some extra zuchinni that I have in my fridge. This is great!
Sula
So glad you like it!
Big Trouble
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!
Sula
It's definitely worth a try. Depending upon how much flavor the vegan cheese has, it might be worth increasing the spices. Maybe?
Sula
Oh, and by the way, I did try it recently with broccoli and LOVED it!