This French Onion Chicken Noodle Casserole is filled with delicious noodles smothered in a creamy French onion sauce. It’s easy to make with leftover or rotisserie chicken and your favorite onion dip!
French Onion Chicken Noodle Casserole
Friends, get ready to make the most flavorful casserole of your life. It’ll take you a little bit of time to get those onions to caramelize, but the taste of this casserole is well worth it.
This is a great recipe to use with leftover or rotisserie chicken for an added shortcut.
If you don’t have pre-cooked chicken, searing seasoned chicken breasts in the pot before you caramelize the onions adds even more flavor to the sauce.
The pasta is then gently boiled in chicken and beef broth the same pot as the caramelized onions.
Finally, we top it all of with flaky, golden Puff Pastry!
How to Make it
See recipe card at the bottom of post for ingredient quantities and full written instructions
Season and sear the chicken in vegetable oil until golden brown on both sides. Remove and leave 1 Tablespoon oil in the pot. Add the butter and onions. Toss to coat.
Caramelize the onions, stirring occasionally, reduce heat if needed to allow them to cook low and slow until they reduce and turn a caramel color. Add fresh thyme.
Add water, chicken broth, and beef broth. Bring to a gentle boil and add Rotini. Allow it to gently boil for about 7 minutes, until no more than Al Dente
Transfer to a lightly greased 9 x 13 casserole dish. Top with puff pastry and brush with egg wash if desired.
Bake at 400 degrees for 20 minutes. Serve!
PRO Tip: Don’t remove the puff pastry from the fridge until you’re ready to use it.
Refrigerate for 3-4 days in an airtight container or freeze for up to 3 months.
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French Onion Chicken Noodle Casserole
- 2-3 Tablespoons Vegetable Oil
- 2 small boneless/skinless chicken breasts, or 2 cups cooked chicken
- 2 Tablespoons Italian Seasoning
- 4 Tablespoon unsalted butter
- 2 extra-large yellow onions, or 1.5 pounds
- 2 springs fresh thyme
- 2 ½ chicken broth
- 1 cup beef broth
- 1 cup water
- 1 lb. Rotini pasta, or similarly sized pasta
- 1 cup onion dip mix, see notes
- 1 can cream of chicken soup, (10.5 oz.)
- 2 cups low moisture mozzarella cheese, shredded
- 1 13 oz. roll Wewalka Puff pastry, found in the refrigerator section
- 1 egg + 1 splash cold water - Optional
- Preheat oven to 400 degrees.
- Slice the onions ¼ inch thick and set aside. A mandoline slicer makes this quick and easy.
- Shred the mozzarella and set aside. Low moisture mozzarella shredded from a block melts the best.
Cook the Chicken. (Shortcut: Use 2 leftover cooked chicken or rotisserie chicken.)
- Butterfly the chicken and cut the seam to create two thinner pieces of equal size. Pat dry and season with Italian seasoning, salt, and pepper.
- Heat the oil in a large pot or dutch oven over medium-high heat. Sear the chicken on each side for 4-5 minutes, until light golden brown. The bottom of the chicken will release from the pan once searing is complete.
- Carefully remove the chicken and leave 1 tablespoon of oil in the pot. Let the chicken rest for 5-8 minutes prior to cutting into bite-sized cubes.
Caramelize the Onions
- Reduce heat to medium and melt the butter. Add the onion slices and toss to coat.
- Partially cover and stir occasionally. Reduce heat if they begin to cook too quickly.
- Allow them to reduce significantly over the course of 40 minutes, they will eventually turn a caramel color and begin to foam. (See post above for visual.)
- Add the thyme towards during the last few minutes of cooking.
Cook the Pasta
- Add the chicken broth, beef broth, and water to the pot. Bring to a gently boil and add the pasta.
- Let the pasta gently boil uncovered for about 7 minutes, until no more than al dente. Stir occasionally.
Assemble the Casserole
- Remove from heat. Add the onion dip, cream of chicken soup, mozzarella cheese, and cubed chicken. Stir to combine.
- Transfer to a lightly greased 9 x 13 casserole dish.
- Remove the puff pastry from the fridge and gently unroll. Place it over the casserole dish and use a paring knife to remove excess dough around the edges.
- Optional: Combine the egg + a splash of cold water, whisk to combine and brush a very light coating over the top of the pastry.
- Bake at 400 degrees for 20 minutes. Remove from the oven and serve!
For saucier pasta, use ¾ lb. instead of a full pound.