Mexican Spaghetti Squash Casserole

The smell of cumin and roasting squash always takes me back to a rainy Tuesday when I needed something comforting but not heavy. I had this enormous spaghetti squash sitting on my counter for days, mocking me every time I walked past. Rather than do the usual pasta sauce routine, I decided to lean into the Mexican flavors I was craving.

My roommate walked in while this was bubbling away in the oven and immediately asked what smelled so amazing. We ended up eating it straight from the baking dish while standing at the counter, too impatient to bother with proper plates.

Ingredients

• 1 large spaghetti squash: Look for one that feels heavy for its size with a hard, unblemished skin
• 1 medium red bell pepper: The sweetness balances the smokiness of the spices beautifully
• 1 small red onion: Red onion has a milder bite that works perfectly here
• 2 cloves garlic: Fresh minced garlic makes such a difference compared to jarred
• 1 jalapeño: Leave the seeds in if you want more heat, though I usually remove them
• 1 cup frozen corn: Adds little pops of sweetness throughout
• 1 can black beans: Rinse them well to remove the canning liquid
• 1 can diced tomatoes: Drain thoroughly so your casserole doesnt get watery
• 1½ tsp ground cumin: This is the backbone of the Mexican flavor profile
• 1 tsp chili powder: Not actually spicy, just adds depth and warmth
• 1 tsp smoked paprika: The smokiness is what makes this taste special
• ½ tsp dried oregano: A classic Mexican herb that ties everything together
• ½ tsp salt: Adjust based on your personal preference
• ¼ tsp black pepper: Freshly ground makes a noticeable difference
• 1 cup shredded cheddar cheese: Sharp cheddar gives the best flavor
• ½ cup Monterey Jack cheese: Melts beautifully and adds creaminess
• ¼ cup chopped fresh cilantro: The bright fresh finish cuts through the richness
• 1 lime: A squeeze of lime right before serving makes everything pop

Instructions

Roast the spaghetti squash:

Cut the squash in half lengthwise and scoop out those seeds. Rub the cut sides with a little olive oil and place them cut side down on a parchment lined baking sheet. Let them roast at 400°F for about 35 to 40 minutes until a fork slides easily into the flesh.

Sauté the vegetables:

While the squash roasts, cook the onion, bell pepper, jalapeño, and garlic in a skillet with olive oil over medium heat. Let them soften for 4 to 5 minutes until fragrant and starting to brown slightly.

Build the filling:

Add the corn, black beans, and drained tomatoes to the skillet. Sprinkle in all those spices and give everything a good stir. Let it cook together for 3 to 4 minutes so the flavors can mingle.

Shred and combine:

Once the squash is cool enough to handle, use a fork to scrape the flesh into strands. Mix it with the vegetable filling and half of both cheeses in a large bowl.

Assemble and bake:

Turn your oven down to 375°F. Spread the mixture in a greased 9x13 inch baking dish and top with the remaining cheese. Bake for 20 to 25 minutes until everything is hot and bubbling with golden spots on top.

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This recipe became my go to for potlucks after my coworkers kept asking me to bring it. Something about the combination of familiar Mexican flavors with the unexpected squash texture really wins people over.

Making It Your Own

I have learned that this casserole is incredibly forgiving. You can add cooked chicken or ground beef if you want more protein, or swap in pinto beans instead of black beans. The beauty is in the spice blend which works with almost any protein or bean.

Make Ahead Magic

You can assemble the entire casserole up to 24 hours before baking. Just cover it tightly and refrigerate, then add about 5 extra minutes to the baking time if it is cold from the fridge. The flavors actually get better after sitting together for a while.

Serving Suggestions

A dollop of sour cream and some sliced avocado take this over the top. I also love setting out hot sauce so everyone can adjust the heat level to their liking.

• Warm your tortillas while the casserole rests for a few minutes
• A simple green salad with lime vinaigrette balances the richness perfectly
• Leftovers reheat beautifully in the microwave for lunch the next day

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There is something deeply satisfying about turning a simple squash into such a hearty, flavorful meal. I hope this brings as much comfort to your table as it has to mine.

Recipe FAQs

→ Can I make this ahead of time?

Yes, you can assemble the entire casserole up to 24 hours in advance and refrigerate it before baking. Add 5-10 minutes to the baking time if baking straight from the refrigerator.

→ How do I store leftovers?

Store leftover portions in an airtight container in the refrigerator for up to 4 days. Reheat individual portions in the microwave or cover the entire dish with foil and warm in a 350°F oven.

→ Can I freeze this casserole?

Yes, this freezes well. Assemble the unbaked casserole, wrap tightly in plastic and foil, and freeze for up to 3 months. Thaw overnight in the refrigerator before baking.

→ What can I serve with this?

Top with sliced avocado, sour cream, or your favorite hot sauce. A simple green salad or Mexican rice makes excellent sides. The lime wedges add a bright, fresh finish.

→ How do I know when the spaghetti squash is done roasting?

The squash is ready when the flesh is tender and easily shreds into strands with a fork. This typically takes 35-40 minutes at 400°F. Let it cool slightly before handling.

→ Can I add meat to this?

Absolutely. Cooked shredded chicken or browned ground turkey make excellent additions. Add about 2 cups of cooked meat when combining the squash with the vegetable mixture.