French Onion Chicken Orzo Casserole

This casserole takes everything you love about French onion soup — slow-sweet caramelized onions, savory melted cheese, and a glossy, beefy finish — and folds it into creamy orzo and shredded chicken. It’s weeknight comfort food with a touch of elevated bistro flavor, perfect when you want one-pan ease and crowd-pleasing results.

Why you’ll love this dish

This recipe turns humble pantry staples into something special: caramelized onions lend deep sweetness, orzo makes a silky, risotto-like base without constant stirring, and shredded rotisserie chicken keeps it fast. It’s quick enough for a busy weeknight yet cozy enough for a casual dinner party.

“A dinner that tastes like you slow-cooked it all day, but comes together in under an hour — pure comfort.” — home cook review

If you enjoy simple, flavorful chicken dinners and party bites, you might also like this party-ready stuffed chicken appetizer that’s great for gatherings.

Step-by-step overview

This is the high-level flow so you know what to expect before you start:

• Caramelize onions in butter and oil until richly golden (this is the flavor backbone).
• Toast orzo briefly with the onions to coat and unlock nuttiness.
• Stir in cooked chicken, herbs, and liquids; simmer until orzo is tender and creamy.
• Fold in most of the cheese, then bake briefly to brown and bubble a cheesy top.
• Rest, garnish, and serve.

You’ll need an oven-safe skillet or Dutch oven to go from stovetop to oven without extra dishes.

Key ingredients

• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 large yellow onions, thinly sliced (about 3–4 cups)
• 1 teaspoon sugar (helps caramelization)
• 1/2 teaspoon salt, plus more to taste
• 3 garlic cloves, minced
• 1 1/2 cups orzo pasta
• 2 cups cooked shredded chicken (rotisserie chicken works great)
• 1/2 teaspoon dried thyme
• 1/4 teaspoon black pepper
• 2 cups low-sodium chicken broth
• 1 cup heavy cream (or half-and-half to lighten)
• 1 1/2 cups shredded mozzarella, divided
• 1/2 cup grated Parmesan
• Optional: 1/2 teaspoon Worcestershire sauce or a drizzle of balsamic glaze for extra umami

Notes and substitutions:

• Swap half-and-half for heavy cream to reduce richness.
• For vegetarian version, replace chicken with mushrooms and use vegetable broth (see Variations).
• To reduce sodium, use unsalted broth and add salt at the end to taste.

Step-by-step instructions

1. Preheat and prepare: Preheat oven to 375°F (190°C). Use an oven-safe 10–12" skillet or Dutch oven.
2. Melt fats: Over medium heat, melt 2 tablespoons butter with 1 tablespoon olive oil.
3. Caramelize onions: Add sliced onions, 1 teaspoon sugar, and 1/2 teaspoon salt. Cook, stirring occasionally, 20–25 minutes until deep golden and sweet. Be patient — flavor develops with slow cooking.
4. Add garlic: Stir in minced garlic during the last 1–2 minutes and cook until fragrant.
5. Toast orzo: Add 1 1/2 cups orzo and toast 1–2 minutes, stirring so grains are coated with onion mixture. This step adds nuttiness and helps keep orzo from becoming gluey.
6. Combine chicken and seasoning: Stir in 2 cups shredded cooked chicken, 1/2 teaspoon dried thyme, 1/4 teaspoon black pepper, and optional Worcestershire sauce. Mix to combine.
7. Add liquids: Pour in 2 cups low-sodium chicken broth and 1 cup heavy cream. Increase heat to bring to a gentle simmer.
8. Simmer covered: Reduce heat to low, cover, and simmer 8–10 minutes, stirring occasionally, until orzo is tender but not mushy (timing depends on brand).
9. Cheese in: Stir in 1 cup mozzarella and 1/2 cup Parmesan until melted into a creamy sauce. Taste and adjust seasoning.
10. Bake for finish: Top with remaining 1/2 cup mozzarella. Transfer skillet to preheated oven and bake uncovered 10–15 minutes until bubbly and the top is golden.
11. Rest and serve: Let rest 5–10 minutes to thicken. Garnish with fresh thyme or chopped parsley, then serve.

Safety note: Because the chicken is pre-cooked, the bake is for texture and flavor; ensure filling reaches a simmer and is piping hot before serving.

What to serve it with

• Simple green salad with a lemon vinaigrette to cut the richness.
• Roasted or steamed green vegetables: broccolini, green beans, or asparagus.
• Crusty bread for sopping up the creamy sauce, or a crisp baguette.
• For wine: a unoaked Chardonnay or a light Pinot Noir complements the savory-sweet onions and creamy cheese.

Pair it with easy roasted veggies and a light salad for weeknight balance, or present it straight from the skillet at a casual dinner party.

Storage and reheating tips

• Refrigerator: Transfer cooled casserole to an airtight container or cover skillet tightly. Keeps 3–4 days.
• Freezing: Portion into freezer-safe containers and freeze up to 3 months. Thaw overnight in the refrigerator before reheating.
• Reheating (oven): Reheat covered at 325°F (160°C) until warmed through, about 15–25 minutes for a single portion, longer for larger portions.
• Reheating (microwave): Reheat individual servings on medium power in short bursts, stirring between intervals to distribute heat evenly. Add a splash of cream or broth if it looks dry.
• Food safety: When reheating chicken-based dishes, heat to an internal temperature of 165°F (74°C).

Pro chef tips

• Don’t rush the onions: True French onion flavor comes from slow caramelization. Use medium-low heat and scrape browned bits from the pan.
• Use rotisserie chicken to save time — it adds flavor and texture without extra cooking.
• Toasting the orzo prevents it from releasing too much starch into the sauce.
• If your sauce gets too thick after baking, stir in a few tablespoons of warm broth or cream to loosen it.
• Use an oven-safe skillet so you can go stovetop-to-oven without transferring, which preserves the fond.

For more techniques on cooking perfect chicken ahead of time, check this guide to juicy baked chicken breast techniques that also apply when preparing chicken for casseroles and weeknight meals.

Creative twists

• Cheese swap: Replace mozzarella with Gruyère for a classic French onion note, or fontina for extra meltiness.
• Vegetarian: Omit chicken; add 12–16 oz sliced cremini or shiitake mushrooms and use vegetable broth. Sauté mushrooms until browned before adding orzo.
• Gluten-free: Use a gluten-free orzo or substitute short-grain rice (adjust liquid and cook time).
• Add greens: Stir in a few handfuls of baby spinach or kale at the end until wilted.
• Make it smoky: Stir in 1/2 teaspoon smoked paprika or use smoked mozzarella for a subtle smoke layer.
• Finish with acid: A drizzle of balsamic glaze or a splash of Sherry before serving brightens the rich flavors.

Common questions

Q: How long does this take start to finish?
A: Active hands-on time is about 15–20 minutes (mostly onion attention). Total time including caramelizing and bake is roughly 50–60 minutes.

Q: Can I use raw chicken instead of cooked shredded chicken?
A: You can, but you’ll need to cut raw chicken into small bite-sized pieces and cook them through in the skillet before adding liquids — add an extra 6–10 minutes and ensure the chicken reaches 165°F. Using pre-cooked chicken (rotisserie) keeps the bake fast and moist.

Q: Is orzo the same as rice? Can I use rice instead?
A: Orzo is a small pasta shaped like rice; it cooks faster and creates a creamier texture. You can substitute short-grain rice, but you’ll need to increase the liquid and simmer time (typically 1:2.25 rice-to-liquid ratio and 18–20 minutes).

Q: Can I make this ahead and bake later?
A: Yes. Prepare through Step 8 (simmer until orzo is nearly tender), cool, cover, and refrigerate up to 24 hours. When ready, stir in cheeses, top with remaining mozzarella, and bake 10–15 minutes until bubbly.

Q: How do I reduce calories or fat?
A: Use half-and-half instead of heavy cream, reduce the cheese slightly, and swap part of the mozzarella for a lower-fat cheese. Adding more vegetables (mushrooms, spinach) also stretches the dish without much added fat.

If you need clarification on any step, substitutions, or timing, ask and I’ll walk you through it. Enjoy a skillet dinner that tastes indulgent but is surprisingly simple to make.

French Onion Chicken Casserole

This casserole combines the flavors of French onion soup into a creamy orzo with chicken, topped with melted cheese, creating quick and comforting weeknight food.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 30 minutes mins

Total Time 1 hour hr

Course Dinner, Main Course

Cuisine American, French

Servings 4 servings

Calories 500 kcal

Ingredients

  

For the casserole

• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 large yellow onions, thinly sliced (about 3–4 cups)
• 1 teaspoon sugar (helps caramelization)
• 1/2 teaspoon salt (plus more to taste)
• 3 cloves garlic, minced
• 1 1/2 cups orzo pasta
• 2 cups cooked shredded chicken (rotisserie chicken works great)
• 1/2 teaspoon dried thyme
• 1/4 teaspoon black pepper
• 2 cups low-sodium chicken broth
• 1 cup heavy cream (or half-and-half to lighten)
• 1 1/2 cups shredded mozzarella, divided
• 1/2 cup grated Parmesan
• 1/2 teaspoon Worcestershire sauce (optional, for extra umami)

Instructions

 

Preparation

• Preheat oven to 375°F (190°C) and prepare an oven-safe 10–12" skillet or Dutch oven.
• Melt 2 tablespoons butter with 1 tablespoon olive oil over medium heat.
• Add sliced onions, 1 teaspoon sugar, and 1/2 teaspoon salt. Cook, stirring occasionally, for 20–25 minutes until deep golden and sweet.
• Stir in minced garlic during the last 1–2 minutes of cooking.
• Add 1 1/2 cups orzo and toast for 1–2 minutes, stirring to coat in the onion mixture.
• Stir in 2 cups shredded cooked chicken, 1/2 teaspoon dried thyme, 1/4 teaspoon black pepper, and optional Worcestershire sauce.
• Pour in 2 cups low-sodium chicken broth and 1 cup heavy cream. Increase heat to bring to a gentle simmer.
• Cover and reduce heat to low. Simmer for 8–10 minutes, stirring occasionally, until orzo is tender but not mushy.
• Stir in 1 cup mozzarella and 1/2 cup Parmesan until melted into a creamy sauce.

Baking and Serving

• Top with remaining 1/2 cup mozzarella and transfer skillet to preheated oven. Bake uncovered for 10–15 minutes until bubbly and the top is golden.
• Let rest for 5–10 minutes before serving. Garnish with fresh thyme or chopped parsley.

Notes

For a vegetarian version, replace chicken with mushrooms and use vegetable broth. You can also use half-and-half to reduce richness. To reduce sodium, use unsalted broth.

Keyword Casserole, chicken dinner, Comfort Food, French onion, one pan meal