Keto Mexican Spaghetti Squash Casserole

If you are looking for some low carb comfort food, try this keto Mexican spaghetti squash casserole. The veggie noodles are mixed with chicken, beans and other tasty ingredients to give you a creamy, cheesy keto casserole. Each serving has only 9 grams net carbs and 37.4 grams protein.

You might also like this popular low carb Mexican chicken casserole.

We did not grow any spaghetti squash this year but now that they are popping up at Aldi every week I started craving them. If you have never tried spaghetti squash I urge you to try it because it’s fun to eat, delicious, healthy and pretty low carb.

Today I made this keto Mexican spaghetti squash casserole and it does not disappoint. I mixed the veggie noodles in with cooked chicken and other ingredients to make a creamy mixture that is topped with cheese. I froze the leftovers for a quick low carb lunch too!

Is spaghetti squash low carb?

Spaghetti squash is a great low carb alternative to pasta but it does have carbs. A cup of cooked spaghetti squash has 41.9 calories, 10g carbs and 2.2g of fiber. Therefore it has 7.8g of net carbs per cup.

I like to make it with low carb ingredients so that you can have a smaller portion and still get that pasta experience. So in my opinion spaghetti squash is low carb and keto but you have to watch how much you eat of it. 

I have lots of low carb spaghetti squash recipes on this blog if you too are a fan. 

3 ways to cook spaghetti squash.

Lately I cook spaghetti squash in the Instant Pot because it’s so easy however there 3 ways that I have cooked it and here they are.

1. Instant Pot: You just stack the 2-4 cleaned halves in the pot (using the trivet that came with it), along with 1 cup of water and pressure cook for 5 minutes. Use the quick release to bring it down from pressure. Let cool then scrape out the insides. 
2. Microwave: Add the cleaned spaghetti squash to a baking dish with a little water and cook for  12 – 15 minutes until it is fork tender. Let cool before scraping out the insides. 
3. Baked in Oven: Cut and clean out the seeds of the spaghetti squash and place face down in a baking dish with a little bit of water. Bake in a 400°F oven for about 40 minutes. If you can pierce it with a fork it is done. Depending on the size it might take more time so cook a little longer if you don’t think it’s done. 

Recipe ingredients I used and substitutions.

The simple ingredients I used were cooked rotisserie chicken, black soy beans, chunky salsa, spices (cumin, chili powder, oregano), cheddar and gouda cheese, cream cheese, cilantro and cooked spaghetti squash. If you want to season with salt and black pepper too you can but I didn’t think it was necessary. You can also add some hot pepper flakes if you want to add more heat.

Black Soy Beans
I like to use black soy beans as a low carb substitute for black beans which are high in carbs. So if you miss beans in Mexican foods like chili or casseroles give them a try. They have the black bean flavor and texture but a ½ cup has only 5 grams net carbs and 11 grams of protein. I have only used this Eden brand of black soy beans and they are great.

If you don’t care about carbs you can use regular black beans and even things like corn which are higher in carbs but often in Mexican casseroles.

Chunky Salsa
Surprisingly most jar salsas are pretty low in carbs and when you use them in recipes like this they cover a lot of ingredients – vegetables (tomatoes, bell peppers, onions), garlic, seasonings, etc. I use chunky salsa from Aldi. You can use your favorite brand of salsa just try to get the one with the lowest carbs.

Cheeses
The cream cheese adds creaminess and the cheddar cheese adds flavor. I like the gouda cheese too because it’s very melty. You can substitute mozzarella, Colby Jack, Monterey Jack, etc for the Colby or even just more shredded cheddar cheese.

Rotisserie Chicken
I always free chopped rotisserie chickens or low carb casserole dishes, soups or stews. However you can also use any kind of leftover chicken. This recipe just uses cooked chicken so any kind will work.

You could also use other cooked meat like cooked turkey, ground beef, taco meat, ground turkey, ground chicken etc. However make sure they are cooked before adding to the dish.

Note I use fresh cilantro leaves in this recipe but if you don’t like the flavor just eliminate it.

How to make keto Mexican spaghetti squash casserole

Step 1: Preheat oven to 350°F. Get out a large baking dish and spray with nonstick cooking spray.

Step 2: Cook your spaghetti squash anyway you want. Check above for the 3 ways to do it. When done, scrape the sides with a fork and scoop the stringy flesh out into a bowl and set aside. However keep the shells or skin to use for serving.

Step 3: Get out a large skillet and heat to medium heat. Add the cream cheese, cooked chicken and soy beans to the pan and mix well once the cream cheese starts to melt.

Step 4: Mix well to make the cheese melt. Then add the cooked spaghetti squash, spices, half of the cheddar cheese and cilantro (if using). Mix it well again.

Step 5: Spoon into the skins or shells that you saved and then top with salsa, remaining cheddar and gouda cheeses. Place in the preheated oven and 20-30 minutes until the cheeses turn golden brown and melty.

Let cool before serving. Garnish with additional cilantro if you wish or even add some sour cream or other toppings. Store leftover in an airtight container. Please scroll down to view the printable recipe card.

This meal really has everything you want in it. You have the protein, starch and veggies all in one. However if you want to make it a complete meal you can add a green salad and that should be good. We just ate it as is.

More healthy spaghetti squash recipes to try.

One of the reasons I like making spaghetti squash in the Instant Pot is that you can cook 2 whole squashes at once. I like to store cooked spaghetti squash in refrigerator for lots of low carb dishes like these:

• low carb goat cheese and walnut spaghetti squash
• coconut basil shrimp spaghetti squash (see pic below)
• keto spaghetti squash breakfast casserole
• low carb spaghetti squash pizza  skillet

I hope you like this as much as I did. It was creamy, cheesy and full of all those Mexican casserole flavors. The spaghetti squash even gives it a hint of sweetness. 

If you decide to freeze this, just scoop into containers after it’s baked and reheat in the microwave for 3-5 minutes.

NOTE: I change the serving amount to be 4 servings instead of 6. And so the revised nutritional information for 1 serving is: 340 calories / 15.2g fat / 12.7g carbs / 3.7g fiber / 37.4g protein = 9g net carbs.