French Onion Chicken Orzo Casserole

French Onion Chicken Orzo Casserole is a cozy, all-in-one baked dish that marries deeply caramelized onions with tender shredded chicken and creamy orzo. I first made it on a rainy weeknight when I had leftover rotisserie chicken and two stubborn yellow onions in the crisper; the result felt like French onion soup had tucked into a casserole dish and invited pasta to the party. It’s an easy crowd-pleaser—rich, cheesy, and comforting without being fussy. If you like hearty, cheesy bakes, you might also enjoy this cottage cheese breakfast casserole for another make-ahead, family-friendly option.

Why you’ll love this dish

• Big flavor from simple steps: slow-caramelized onions give a deep, sweet-savory backbone that lifts the whole casserole.
• Weeknight-friendly: using pre-cooked chicken (rotisserie or leftovers) cuts hands-on time drastically.
• Pantry-flexible: orzo cooks in the same pan with the liquids, so you get creamy texture without separate pots.
• Kid- and crowd-approved: familiar cheesy notes make this an easy win for picky eaters and potlucks.
• Make-ahead and freezer-friendly: assemble ahead to bake later, or freeze for busy evenings.

“A casserole that tastes like a restaurant’s French onion—but easier and made at home.” — a note I hear from friends after serving this.

The cooking process explained

Before you start, here’s the quick plan so you know what to expect:

1. Slowly caramelize thinly sliced onions in butter and olive oil until deeply golden and sweet.
2. Add garlic briefly, then stir in dry orzo so it toasts lightly.
3. Fold in shredded cooked chicken and seasonings.
4. Add chicken broth and cream, simmer until the orzo is tender and saucy.
5. Stir in most of the cheese, top with the rest, then finish in a hot oven until bubbly and golden.
6. Rest briefly, garnish, and serve.

This approach keeps active time low while building lots of flavor.

What you’ll need

• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 large yellow onions, thinly sliced
• 1 teaspoon sugar
• 1/2 teaspoon salt
• 3 garlic cloves, minced
• 1 1/2 cups orzo pasta
• 2 cups cooked shredded chicken (rotisserie works well)
• 1/2 teaspoon dried thyme
• 1/4 teaspoon black pepper
• 2 cups low-sodium chicken broth
• 1 cup heavy cream (or half and half for a lighter option)
• 1 1/2 cups shredded mozzarella cheese (reserve 1/2 cup for topping)
• 1/2 cup grated Parmesan cheese
• Optional: 1/2 teaspoon Worcestershire sauce or a splash of balsamic glaze for added depth

Substitutions/notes: use olive oil if you prefer no butter (flavor will change). For a lighter dish, use half-and-half or whole milk, but reduce simmer time and watch texture. Gruyère or fontina can replace mozzarella for a nuttier finish.

Step-by-step instructions

1. Caramelize the onions: In a large oven-safe skillet or Dutch oven, melt the butter with the olive oil over medium heat. Add the sliced onions, sugar, and 1/2 teaspoon salt. Cook, stirring occasionally, for 20–25 minutes until the onions are deeply golden and jammy. If they start to stick, lower the heat slightly and add a splash of water to loosen the fond. Stir in the minced garlic for the last 1–2 minutes.
2. Add the orzo and chicken: Stir the orzo into the skillet and cook for about 2 minutes to lightly toast the grains. Add the shredded chicken, dried thyme, and black pepper. If using, stir in the Worcestershire sauce now.
3. Pour in the liquids: Pour the chicken broth and cream over the mixture. Bring it to a gentle simmer, then reduce the heat to low. Cover and cook for 8–10 minutes, stirring occasionally, until the orzo is tender and has absorbed most of the liquid. If the mixture seems too thick before the orzo is done, add a bit more broth.
4. Add the cheese: Remove the lid and stir in 1 cup of the mozzarella and all the Parmesan until melted and creamy. Taste and adjust seasoning.
5. Bake the casserole: Preheat the oven to 375°F (190°C). Sprinkle the reserved 1/2 cup mozzarella over the top. Bake uncovered for 10–15 minutes, or until the top is bubbly and golden.
6. Serve: Let the casserole rest for 5–10 minutes to set. Garnish with fresh thyme or chopped parsley if you like.

Serving suggestions

• Spoon generous portions onto warmed plates and garnish with fresh thyme or chives.
• Serve alongside a bright green salad (arugula with lemon vinaigrette) to cut the richness.
• For a rustic meal, add toasted baguette slices or garlic bread for sopping up creamy edges.
• For game-day spreads, this pairs well with bold flavors — try it after a tangy dip like the buffalo chicken dip with cottage cheese as part of a comforting buffet.
• Wine pairing: a medium-bodied Chardonnay or a light Pinot Noir match the dish’s savory-sweet profile.

Storage and reheating tips

• Refrigerator: Cool the casserole to room temperature, cover tightly, and store up to 3–4 days.
• Reheating: Reheat individual portions in the microwave (covered) for 1–2 minutes, stirring halfway. For the oven, cover with foil and bake at 350°F (175°C) until heated through, about 15–20 minutes. Add a splash of broth or cream if it looks dry.
• Freezing: Freeze in an airtight container for up to 2 months. Thaw overnight in the refrigerator before reheating. For best texture, you can freeze before baking, then bake from thawed state, adding a few extra minutes if needed.
• Food safety: Don’t leave the casserole at room temperature for more than 2 hours. Reheat leftovers to 165°F (74°C) before serving.

Pro chef tips

• Patience with onions pays off: low and slow caramelization (20–25 minutes) yields the classic sweet-savory backbone — rushing this step sacrifices depth.
• Toast the orzo briefly: that 1–2 minute toast gives a nutty note and helps the pasta hold shape during baking.
• Use low-sodium broth so you can control salt; the cheeses and any Worcestershire already add sodium.
• If your skillet isn’t ovenproof, transfer everything to a lightly greased 9×13-inch baking dish before topping and baking.
• Make-ahead trick: complete steps through adding the cheese, then cool and refrigerate. When ready, top with remaining cheese and bake 20–25 minutes until bubbly.

Recipe variations

• Vegetarian: Swap shredded chicken for a mix of sautéed mushrooms and white beans; use vegetable broth.
• Lighter: Use half-and-half instead of heavy cream and reduce the final bake time to preserve moisture.
• Cheese swap: Replace mozzarella with grated Gruyère for a more “French” finish.
• Extra greens: Stir in a few handfuls of baby spinach or kale at the end of the stovetop simmer so the leaves wilt but stay bright.
• Extra crisp: After baking, broil 1–2 minutes to get a blistered, golden-top crust — watch carefully to avoid burning.

Your questions answered

Q: How long does this take from start to finish?
A: Active time is about 25–35 minutes (mostly onions and assembly). With baking and resting, plan 50–60 minutes total.

Q: Can I use raw chicken instead of cooked shredded chicken?
A: It’s not recommended to add raw chicken here because the orzo’s cook time is short. If using raw chicken breasts, cook them separately (poach, roast, or dice and sauté) until done, then add. Alternatively, shred leftover rotisserie chicken for speed.

Q: Can I substitute the heavy cream with milk?
A: Yes, but whole milk will produce a thinner sauce. To maintain creaminess without heavy cream, use half-and-half or add a tablespoon of butter and a splash of flour to thicken slightly.

Q: Is this safe to freeze after baking?
A: Yes — but texture of the cream and cheese can change slightly. For best results, freeze before the final bake and thaw overnight before baking; this preserves texture better.

Q: Can I make this in a slow cooker?
A: Many slow-cooker versions exist, but because orzo can overcook into mush, adaptations often add orzo near the end. If you want a slow-cooker route, watch orzo closely and consider using larger pasta shapes or rice that hold up better; alternately, look for dedicated slow-cooker recipes designed for pasta.

Conclusion

If you want a hands-off, richly flavored casserole that tastes like French onion soup crossed with a cheesy pasta bake, this recipe delivers. For a slow-cooker take on similar flavors, check out Crockpot Creamy French Onion Chicken and Orzo.

French Onion Chicken Orzo Casserole

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• Author: amir_hassan
• Total Time: 60 minutes
• Yield: 4 servings
• Diet: Poultry

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Description

A cozy, all-in-one baked dish that combines caramelized onions, tender shredded chicken, and creamy orzo for a comforting meal.

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Ingredients

• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 large yellow onions, thinly sliced
• 1 teaspoon sugar
• 1/2 teaspoon salt
• 3 garlic cloves, minced
• 1 1/2 cups orzo pasta
• 2 cups cooked shredded chicken
• 1/2 teaspoon dried thyme
• 1/4 teaspoon black pepper
• 2 cups low-sodium chicken broth
• 1 cup heavy cream
• 1 1/2 cups shredded mozzarella cheese (reserve 1/2 cup for topping)
• 1/2 cup grated Parmesan cheese
• Optional: 1/2 teaspoon Worcestershire sauce or a splash of balsamic glaze

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Instructions

1. Caramelize the onions: In a large oven-safe skillet, melt the butter with the olive oil over medium heat. Add the sliced onions, sugar, and salt. Cook for 20–25 minutes until deeply golden. Stir in the minced garlic for the last 1–2 minutes.
2. Add the orzo and chicken: Stir the orzo into the skillet and lightly toast for 2 minutes. Add the shredded chicken, thyme, and black pepper. Stir in Worcestershire sauce if using.
3. Pour in the liquids: Add chicken broth and cream, bring to a simmer. Cover and cook for 8–10 minutes until orzo is tender.
4. Add the cheese: Stir in 1 cup mozzarella and all the Parmesan until melted and creamy. Adjust seasoning.
5. Bake the casserole: Preheat oven to 375°F (190°C). Sprinkle reserved mozzarella on top. Bake uncovered for 10–15 minutes until bubbly and golden.
6. Serve: Let rest for 5–10 minutes. Garnish with fresh thyme or parsley if desired.

Notes

For a lighter version, use half-and-half instead of heavy cream. This dish can be prepared ahead of time and stored in the freezer.

• Prep Time: 30 minutes
• Cook Time: 30 minutes
• Category: Main Course
• Method: Baking
• Cuisine: French