Pin it This comforting casserole combines tender spaghetti with shredded chicken breast, diced bell peppers, and onions in a rich, creamy sauce made with Monterey Jack and sharp cheddar cheeses. The dish bakes until golden and bubbly, creating a satisfying main that serves six.
The sauce starts with a classic roux base enriched with whole milk and chicken broth, then finished with sour cream for extra tanginess. Smoked paprika adds subtle depth, while the generous cheese topping becomes beautifully golden in the oven.
The first time I made this Monterey Chicken Spaghetti, it was one of those Tuesdays where everyone needed comfort food immediately. My husband had walked in the door looking exhausted, and I had a rotisserie chicken from the grocery store sitting on the counter. I threw everything together in about twenty minutes, and the way that Monterey Jack cheese bubbled up and turned golden brown made the whole house smell like a cozy restaurant.
Last winter, my sister came over after a terrible day at work, and I made this casserole while she sat at my kitchen counter. She took one bite and actually started crying, then laughing, because sometimes melted cheese and pasta fix what nothing else can reach. Now she texts me every time she makes it, sending photos of her own golden bubbling version.
Ingredients
- Spaghetti: This pasta catches the creamy sauce beautifully, and I have learned to cook it just shy of al dente since it will bake further in the oven.
- Cooked chicken breast: Rotisserie chicken works perfectly here and saves so much time, or use leftover grilled chicken from earlier in the week.
- Red bell pepper: The sweetness balances the rich cheese sauce, and dicing it small helps it distribute evenly throughout every bite.
- Yellow onion: I take my time sauting these until they are translucent and fragrant because that aromatic base makes the whole dish taste developed.
- Garlic: Fresh minced garlic adds that essential aromatic note that makes people ask what is in this sauce.
- Unsalted butter: Starting the roux with butter gives the sauce foundation and a subtle richness that you cannot get from oil alone.
- All-purpose flour: This thickens the cheese sauce into something velvety that coats the spaghetti rather than pooling at the bottom.
- Whole milk: I have tried using lower fat milk but the sauce never quite achieves that luxurious texture that makes this dish feel special.
- Monterey Jack cheese: This melts beautifully and has just enough mild flavor to let the other ingredients shine while still tasting indulgent.
- Sharp cheddar cheese: The sharpness cuts through the richness and adds depth that Monterey Jack alone cannot provide.
- Chicken broth: A splash of broth adds savory depth that makes the cheese sauce taste more complex and less like just melted cheese.
- Sour cream: This is the secret ingredient that makes the sauce incredibly creamy and adds a slight tang that balances the richness.
- Smoked paprika: Just a quarter teaspoon gives the dish a subtle smoky note that makes people wonder what you did differently.
- Green onions: Fresh green onions on top add a bright pop of color and mild onion flavor that cuts through the cheesy richness.
Instructions
- Get the oven ready:
- Preheat to 375F and grease a 9x13 baking dish with butter or cooking spray so nothing sticks to the bottom.
- Cook the spaghetti:
- Boil the pasta in salted water until just al dente, drain well, and set aside while you make the sauce.
- Sauté the vegetables:
- Melt butter in a large skillet over medium heat and cook the onions and peppers for 3 to 4 minutes until they soften, then add garlic for one more minute.
- Build the cheese sauce:
- Stir in the flour for one minute, then gradually whisk in the milk and broth, cooking for 3 to 4 minutes until the sauce thickens noticeably.
- Add the cheese:
- Remove from heat and stir in both cheeses, salt, pepper, and smoked paprika until completely melted and smooth.
- Combine everything:
- Fold in the sour cream, chicken, and cooked spaghetti until the sauce coats every strand evenly.
- Assemble and bake:
- Transfer to your prepared dish, top with the remaining Monterey Jack, and bake for 20 to 25 minutes until bubbly and golden.
- Finish and serve:
- Sprinkle with fresh green onions and let the casserole sit for about five minutes before serving so it sets slightly.
Pin it This recipe became my go-to when my neighbor had her baby last year. I dropped off a pan still warm from the oven, and she messaged me three days later asking for the recipe because her husband kept requesting it. There is something about pasta and cheese that says everything will be okay.
Make It Ahead
I have assembled this casserole the night before and kept it covered in the refrigerator. Just add about five extra minutes to the baking time since it will be cold going into the oven.
Freezing Instructions
Wrap the assembled unbaked casserole tightly in plastic and then foil, and freeze for up to two months. Thaw overnight in the refrigerator before baking as directed.
Serving Suggestions
A crisp green salad with vinaigrette cuts through the richness beautifully. I also like to serve steamed broccoli or roasted asparagus on the side to add something green to the plate.
- Crusty bread for soaking up any extra sauce
- A simple arugula salad with lemon dressing
- Chilled white wine like Chardonnay or Pinot Grigio
Pin it There is something so satisfying about pulling a golden bubbling casserole out of the oven and watching people light up when they see it on the table.
Recipe Q&A Section
- → Can I make Monterey chicken spaghetti ahead of time?
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Yes, assemble the casserole up to 24 hours in advance and refrigerate. Add 10-15 minutes to baking time if baking cold from the refrigerator.
- → What type of chicken works best?
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Cooked chicken breast works beautifully, whether freshly cooked, leftover, or rotisserie chicken. Shredded or diced both integrate well into the creamy sauce.
- → Can I freeze this casserole?
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Freeze the unbaked casserole for up to 3 months. Thaw overnight in the refrigerator before baking as directed.
- → How do I know when it's done baking?
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The casserole is ready when the cheese topping is melted and lightly golden, and the edges are bubbling vigorously, typically 20-25 minutes at 375°F.
- → What sides pair well with this dish?
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A crisp green salad with vinaigrette balances the richness. Roasted vegetables or garlic bread also complement the creamy pasta nicely.
- → Can I add other vegetables?
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Spinach, mushrooms, or diced tomatoes can be added with the bell peppers. Just keep total additions to about 1-2 cups to maintain the sauce consistency.
