The first time I made this Monterey Chicken Spaghetti Casserole, it was a last-minute idea on a drizzly Tuesday. I had just come back from the store with a bag of tortilla chips that accidentally burst in my car—half of them crushed.

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Instead of tossing them, I knew I had to use them for something comforting and a little cheesy. That’s when the idea for this casserole came together in my mind like puzzle pieces. It was one of those evenings when I wasn’t looking for anything fancy—just something warm, easy, and satisfying.

As I stirred the creamy mixture of sour cream, chicken, tomatoes, and cheese, the scent alone started drawing my family into the kitchen. My daughter peeked over the counter, asking what smelled like nachos. By the time it baked, the cheese was bubbling, the edges slightly crisp, and the crushed chips golden and crunchy on top. That first bite? Creamy, cheesy, with a gentle kick from the tomatoes and green chilies—it was exactly what we needed.

Since then, it’s become a regular in our dinner rotation. It’s fast, flavorful, and feeds a crowd. But most of all, it feels like home in a baking dish. I’m sharing the recipe today because I know you’ll love how simple it is and how much joy it brings to the table.

Short Description

Monterey Chicken Spaghetti Casserole is a creamy, cheesy baked dish made with shredded chicken, spaghetti, green chilies, and two types of cheese—topped with optional crushed tortilla chips for a satisfying crunch.

Key Ingredients

2 cups cooked chicken, shredded
8 oz spaghetti, cooked and drained
1 can (10.5 oz) cream of chicken soup
1 can (10.5 oz) diced tomatoes with green chilies, undrained
1/2 cup sour cream
1 cup shredded Monterey Jack cheese
1/2 cup shredded cheddar cheese
1/2 cup green onions, chopped
1 tsp garlic powder
1 tsp onion powder
Salt and pepper, to taste
1/2 cup crushed tortilla chips (optional, for topping)

Tools Needed

9×13-inch baking dish
Large mixing bowl
Wooden spoon or spatula
Saucepan (for cooking spaghetti)
Oven
Measuring cups and spoons

Cooking Instructions

Step 1: Prepare the Chicken and Spaghetti
Preheat your oven to 350°F (175°C). Cook the spaghetti according to package instructions, then drain well. Shred your cooked chicken into bite-sized pieces and set both aside.

Step 2: Mix the Casserole Filling
In a large mixing bowl, combine the shredded chicken, cooked spaghetti, cream of chicken soup, diced tomatoes with green chilies (do not drain), sour cream, garlic powder, onion powder, chopped green onions, and half of the Monterey Jack and cheddar cheeses. Stir until everything is evenly coated. Add salt and pepper to taste.

Step 3: Assemble the Casserole
Grease a 9×13-inch baking dish. Pour the chicken and spaghetti mixture into the dish and spread it out evenly. Sprinkle the remaining Monterey Jack and cheddar cheeses over the top. If using, add a layer of crushed tortilla chips for extra texture.

Step 4: Bake to Perfection
Place the casserole in the oven and bake for 25–30 minutes, or until it’s hot and bubbly and the cheese is melted and golden brown on top. The edges should be lightly crisp.

Step 5: Let It Rest and Serve
Remove the dish from the oven and let it sit for 5–10 minutes before serving. This helps the casserole set and makes slicing easier.

Why You’ll Love This Recipe

– A great way to use leftover chicken or rotisserie chicken

– Kid-friendly flavors with just a hint of spice

– Feeds a family and makes excellent leftovers

– Easy to customize with pantry staples

– One-dish meal—no need for sides if you’re in a hurry

– Perfect for potlucks or casual dinner gatherings

Mistakes to Avoid & Solutions

Mistake 1: Overcooked spaghetti
Solution: Cook your spaghetti until just al dente. Overcooked noodles can become mushy in the casserole.

Mistake 2: Dry casserole
Solution: Don’t drain the tomatoes with green chilies—those extra juices help keep the casserole moist and flavorful.

Mistake 3: Uneven cheese melting
Solution: Always sprinkle cheese evenly and make sure your oven is fully preheated to get that bubbly, golden topping.

Mistake 4: Not seasoning enough
Solution: Taste the mixture before baking and adjust salt and pepper if needed. The soup and cheese already contain salt, but a pinch more may enhance the overall flavor.

Mistake 5: Burnt tortilla topping
Solution: If you’re adding crushed chips, cover the casserole loosely with foil for the first 15 minutes, then remove it to let the chips crisp without burning.

Serving and Pairing Suggestions

This casserole is hearty enough to serve on its own, but here are a few serving ideas:

– Pair it with a crisp green salad or coleslaw to balance the richness

– Serve with roasted or steamed vegetables like broccoli or green beans

– For a casual dinner, offer warm garlic bread or rolls on the side

– Plate it family-style for a relaxed vibe, or pre-slice for individual portions at gatherings

– A light citrus drink or sparkling lemonade pairs well with the cheesy flavors

Storage and Reheating Tips

To Store: Let the casserole cool completely. Store in an airtight container in the fridge for up to 4 days.

To Freeze: Wrap the entire baking dish tightly in foil or transfer portions to freezer-safe containers. Freeze for up to 2 months.

To Reheat (Microwave): Heat individual portions covered with a microwave-safe lid for 1–2 minutes or until hot.

To Reheat (Oven): Cover the baking dish with foil and reheat at 325°F for 20–25 minutes until heated through.

To Refresh Crunchy Topping: Add fresh crushed chips or bake uncovered for the last 5 minutes to crisp it back up.

Tips & Tricks

Use freshly grated cheese for better melting and flavor—pre-shredded cheese often contains anti-caking agents.

Add a handful of frozen corn or black beans to bulk up the casserole with extra texture and nutrition.

Chop your green onions very fine so they blend nicely without overpowering the dish.

If your mixture looks too thick, add a splash of chicken broth or milk.

Let the casserole rest before serving—it helps everything firm up and makes it easier to cut.

Recipe Variations

Tex-Mex Style:
Swap Monterey Jack with pepper jack cheese, add 1/2 tsp cumin and a handful of black beans for a bold Southwestern twist.

Vegetarian Version:
Leave out the chicken, double the diced tomatoes with green chilies, and add sautéed mushrooms, zucchini, or bell peppers.

Creamy Ranch Twist:
Stir 2 tablespoons of ranch dressing mix into the filling and top with crushed buttery crackers instead of tortilla chips.

Low-Carb Option:
Replace spaghetti with spiralized zucchini or cooked spaghetti squash for a lighter, veggie-forward casserole.

Bacon-Lovers Version:
Mix in 1/2 cup cooked, crumbled bacon and top the casserole with extra cheddar for a smoky, savory upgrade.

Final Thoughts

Monterey Chicken Spaghetti Casserole isn’t just another cheesy bake; it’s a dependable, flavor-packed meal that brings people together around the table. Every bite delivers a balance of creamy sauce, melty cheese, and just enough spice to keep things interesting.

It’s the kind of dish that makes your kitchen smell like a cozy diner on a cool evening. I love how flexible it is—add what you like, leave out what you don’t, and it still turns out delicious. If you’re feeding a crowd or simply want leftovers that actually taste better the next day, this recipe checks every box. Keep it in your rotation for those nights when comfort food is the only thing that will do.