Cheesy Spaghetti Squash Casserole

This deliciously cheesy spaghetti squash casserole makes a wonderful side dish and is filling enough to serve as a meatless main course.

Course Side Dish

Cuisine American

Prep Time 15

Cook Time 40

Rest time 10

Total Time 1 5

Servings servings

Calories 226kcal

Olive oil cooking spray
1 (3 pounds) raw spaghetti squash or 2 ½ cups cooked spaghetti squash; 450 grams
1 large egg
½ cup sour cream
1 teaspoon Diamond Crystal kosher salt or ½ teaspoon of any other salt, including Morton kosher salt
¼ teaspoon black pepper
½ teaspoon dried thyme
1 tablespoon fresh garlic minced
1 cup cheddar cheese sharp, shredded

Preheat the oven to 400°F. Lightly spray a 1.5-quart baking dish with olive oil cooking spray.
Olive oil cooking spray

Pierce the spaghetti squash in a few spots with a sharp knife. Microwave it for 6 minutes; turn to the other side and microwave for 6 more minutes until soft to the touch. Let it stand for 5 minutes to finish cooking.
1 (3 pounds) raw spaghetti squash
Using a sharp knife, cut the spaghetti squash in half lengthwise. Allow it to cool for 5 minutes until it's easier to handle. Scoop out the pulp and seeds from the center, then rake a fork back and forth to remove strands of the flesh into a bowl. Set aside.

In a large bowl, lightly whisk the egg. Add the sour cream, kosher salt, black pepper, dried thyme, and minced garlic. Whisk until smooth.
1 large egg, ½ cup sour cream, 1 teaspoon Diamond Crystal kosher salt, ¼ teaspoon black pepper, ½ teaspoon dried thyme, 1 tablespoon fresh garlic
Mix in the cooked spaghetti squash and the shredded cheese.
1 cup cheddar cheese
Transfer the mixture to the prepared baking dish. Bake until browned, about 40 minutes (it will smell wonderful!).
Allow the casserole to cool for 10 minutes, then scoop it onto plates or carefully cut it into squares and serve.

Seasonings, especially salt, are guidelines. Adjust to taste.
You can add more veggies, such as ½ cup of sauteed spinach (drain it well), ½ cup of sauteed mushrooms, ¼ cup of sauteed onions, or ¼ cup of chopped green onions.
Or add a cup of cooked and shredded grilled chicken breast, plus an extra ¼ cup of sour cream, and turn this casserole into a complete meal.
Thanks to the addition of egg, this casserole is sturdy enough to cut into squares. If you'd like to omit the egg, increase the sour cream to ¾ cup and use a large spoon to scoop the casserole onto plates.
You can double this recipe and bake the casserole in a 3.5-quart baking dish, such as the Dutch oven shown in the photos on this page, or a 9 X 13-inch baking dish.
You can keep the leftovers in a sealed container in the fridge for up to 4 days. Reheat them gently in the microwave at 50% power. You can also freeze this casserole. Allow it to cool completely, then wrap it in a layer of plastic wrap and then foil. It can be frozen for up to three months.