French Onion Chicken Orzo Casserole is a warm and comforting dish that brings together tender cooked chicken, orzo pasta, and that rich, sweet flavor of caramelized onions all baked into a cheesy casserole. The dish has a lovely mix of textures—from the soft orzo to the crispy topping, and the depth of flavor from a simple onion soup twist.
I love making this casserole when I want something cozy but easy to put together. The French onion flavor makes it feel special, like a little upgrade from regular pasta and chicken casseroles. I usually use store-bought French onion soup mix to keep things simple, but cooking the onions slowly until they’re golden really makes the dish sing. I find it’s a great way to enjoy that classic onion soup taste without having to stand over the stove for ages.
For serving, I like to pair this casserole with a fresh green salad or some steamed veggies to lighten things up. It’s one of those dishes that leftovers taste even better the next day, so I always make enough for seconds. Plus, it’s the kind of meal that friends and family really seem to appreciate during cooler evenings when something hearty and comforting hits the spot just right.
Key Ingredients & Substitutions
Chicken: Using cooked chicken makes this recipe quick. Rotisserie chicken is a great shortcut. You can also use leftover roasted chicken or even cooked turkey.
Orzo pasta: Orzo absorbs flavors nicely and gives this casserole a creamy texture. If you can’t find orzo, small pasta like acini di pepe or even couscous works well as a substitute.
Onions: Sweet, caramelized onions are the star here. Yellow or sweet onions work best. Patience is key to develop their natural sweetness without burning.
French onion soup mix: This adds rich, familiar flavor quickly. If unavailable, mix dried onion flakes, beef bouillon powder, and a touch of garlic powder as a substitute.
Cheese: Cheddar adds sharpness, mozzarella brings creaminess. Feel free to swap cheddar for Swiss or Gruyère for a slightly different twist.
Bacon: Crispy bacon lends crunch and smoky flavor, but it’s optional. For a vegetarian version, you can skip the bacon or use smoked paprika for that smoky note.
How Do You Get Perfectly Caramelized Onions?
Caramelizing onions adds deep richness but takes patience.
- Slice onions thinly and evenly for uniform cooking.
- Cook on medium-low heat with butter to soften without burning.
- Sprinkle sugar and salt early—this helps draw out moisture and boosts sweetness.
- Stir occasionally, letting onions slowly turn golden brown over 25-30 minutes.
- Don’t rush: the slow cook brings out natural sugars that make the flavor rich and mellow.
Once caramelized, let onions cool before mixing with orzo to keep the flavors balanced. This step makes all the difference in your casserole!
Equipment You’ll Need
- 9×13 inch casserole dish – perfect size for layering and baking the orzo mixture evenly.
- Large skillet – essential for slowly caramelizing the onions without burning them.
- Mixing bowl – makes it easy to combine the orzo, chicken, onions, and seasonings.
- Wooden spoon or spatula – great for stirring onions gently as they caramelize.
- Aluminum foil – helps cover the casserole during baking to keep it moist.
Flavor Variations & Add-Ins
- Swap chicken for cooked ground beef or turkey for a different protein twist.
- Add sautéed mushrooms with the onions to deepen the earthy flavor.
- Use Gruyère or Swiss cheese instead of cheddar for a creamier, nuttier taste.
- Stir in fresh thyme or rosemary to boost the herbal notes alongside the French onion flavor.
How to Make French Onion Chicken Orzo Casserole
Ingredients You’ll Need:
Main Ingredients:
- 2 cups cooked chicken, shredded or diced
- 1 cup orzo pasta, uncooked
- 4 cups chicken broth
- 2 tablespoons butter
- 2 large onions, thinly sliced
- 1 teaspoon sugar
- 1 teaspoon salt, divided
- ½ teaspoon black pepper
- 1 packet (1 oz) French onion soup mix
- 1 cup sour cream
- 1 cup shredded cheddar cheese
- ½ cup shredded mozzarella cheese
Toppings & Garnish:
- 4 slices bacon, cooked and crumbled
- 2 tablespoons fresh parsley, chopped
How Much Time Will You Need?
Preparing and cooking this casserole takes about 1 hour in total. Caramelizing the onions is the most time-consuming step and takes about 25-30 minutes. After mixing everything, baking will take approximately 45-50 minutes. Let the casserole cool for 5 minutes before serving.
Step-by-Step Instructions:
1. Preheat Oven & Prepare Onions:
Preheat your oven to 350°F (175°C). Lightly grease a 9×13 inch casserole dish. In a large skillet, melt the butter over medium heat. Add the sliced onions, then sprinkle with sugar and half of the salt. Slowly cook and stir occasionally for about 25-30 minutes, until the onions are golden, deeply caramelized, and sweet.
2. Mix Orzo and Ingredients:
In a large bowl, combine the uncooked orzo, chicken broth, sour cream, French onion soup mix, remaining salt, and black pepper. Stir well to blend everything evenly. Next, add the cooked chicken and caramelized onions, mixing gently to combine all the flavors.
3. Assemble & Bake the Casserole:
Pour the mixture into the prepared casserole dish. Sprinkle the shredded cheddar and mozzarella cheeses evenly over the top. Add the cooked, crumbled bacon for extra flavor and crunch. Cover the casserole with foil and bake for 35 minutes. Then remove the foil and bake for an additional 10-15 minutes, or until the casserole is bubbly and the cheese is golden brown.
4. Serve & Garnish:
Once baked, remove the casserole from the oven and let it cool for about 5 minutes. Garnish with fresh chopped parsley before serving.
Can I Use Frozen Chicken for This Casserole?
Yes! Just make sure to thaw the chicken completely before using it. Thaw overnight in the refrigerator or use the defrost setting on your microwave. Pat dry to avoid excess moisture.
Can I Prepare This Casserole in Advance?
Absolutely. You can assemble the casserole up to a day ahead. Cover it tightly and refrigerate. When ready to bake, add an extra 5-10 minutes to the baking time if baking straight from the fridge.
How Should I Store Leftovers?
Store leftover casserole in an airtight container in the refrigerator for up to 3 days. Reheat portions in the microwave or oven until warmed through.
What Can I Substitute for French Onion Soup Mix?
If you don’t have French onion soup mix, mix dried onion flakes, beef bouillon powder, garlic powder, and a pinch of sugar for a similar flavor. Adjust amounts to taste.
