Nina Johnson
When the chill of the season sets in and you’re craving something rich, savory, and satisfying, look no further than this French Onion Beef Casserole. It captures all the deep, caramelized flavor of French onion soup and elevates it into a full-fledged meal with tender beef, sweet onions, and melted cheese baked to perfection.
This casserole layers familiar comfort food elements with gourmet flair. Think slow-cooked beef stew meets cheesy baked pasta, all infused with the iconic flavor of deeply caramelized onions. Whether you’re cooking for a weeknight family dinner or hosting a cozy gathering, this dish is always a hit.
What Cut of Beef Works Best for This Casserole?
Chuck roast is the top choice for this casserole because of its marbling, which becomes fall-apart tender during slow cooking. You can also use stewing beef or even leftover pot roast. The key is to let the meat braise slowly until it shreds easily, allowing it to soak up all that French onion flavor.
Ingredients for the French Onion Beef Casserole
Beef chuck roast – Marbled and flavorful, perfect for slow cooking until tender.
Yellow onions – These are essential for caramelization, adding the signature sweetness and depth to the dish.
Garlic – Brings aromatic richness that pairs beautifully with the onions and beef.
Beef broth – A rich base that enhances the savory elements and helps deglaze the pan.
Worcestershire sauce – Adds umami and a hint of tang that balances the sweetness of the onions.
Thyme – A subtle herbal note that complements the beef and onions.
Butter – Helps with onion caramelization and adds depth.
Olive oil – For searing the beef and onions.
All-purpose flour – Used to thicken the sauce slightly, creating a luscious consistency.
Gruyère cheese – Melts into the casserole with nutty, creamy flavor that mimics French onion soup.
Mozzarella cheese – Offers a melty stretch and mild flavor.
Fresh parsley – For garnish and a pop of freshness.
How To Make the French Onion Beef Casserole
Step 1: Sear and Brown the Beef
Cut your chuck roast into large chunks, season with salt and pepper, and sear it in a heavy-bottomed pot with olive oil until browned on all sides. This locks in the juices and builds a flavor base.
Step 2: Caramelize the Onions
In the same pot, add butter and sliced yellow onions. Cook low and slow, stirring often, until they turn a deep golden color. This step takes patience but rewards you with that classic French onion flavor.
Step 3: Add Aromatics and Build the Sauce
Stir in minced garlic, thyme, and a sprinkle of flour. Cook for a minute, then pour in beef broth and Worcestershire sauce, scraping the bottom to deglaze. Bring it to a gentle simmer.
Step 4: Slow Cook the Beef
Return the browned beef to the pot. Cover and let it simmer on low for 2 to 2.5 hours, or until the beef is fall-apart tender. Shred the beef into bite-sized pieces and stir it back into the sauce.
Step 5: Assemble the Casserole
Preheat the oven to 375°F. Transfer the beef-onion mixture into a casserole dish. Top generously with shredded Gruyère and mozzarella cheese.
Step 6: Bake to Golden Perfection
Bake uncovered for 15–20 minutes or until the cheese is bubbly and golden. Sprinkle with chopped parsley just before serving.
How to Serve and Store French Onion Beef Casserole
Serve this casserole hot out of the oven, paired with a crusty baguette or mashed potatoes to soak up the sauce. It also goes beautifully with a simple green salad or roasted vegetables to balance the richness.
To store leftovers, allow the casserole to cool to room temperature before covering and refrigerating. It will keep well for up to 4 days. Reheat in the oven at 350°F, covered with foil, until warmed through. You can also freeze portions for up to 2 months; just thaw overnight in the fridge before reheating.
Frequently Asked Questions
Can I use a different cheese besides Gruyère?
Absolutely! Swiss, provolone, or even white cheddar work well if you want a more accessible substitute.
Do I have to caramelize the onions?
Yes, it’s an essential step. Caramelizing the onions brings out their sweetness and creates the signature flavor base of the casserole.
Can I make this in advance?
You can prepare the beef and onion mixture a day ahead and store it in the fridge. Just assemble with cheese before baking.
What if I don’t have a Dutch oven?
You can sear and prepare everything in a skillet and then transfer to a slow cooker or baking dish for the simmering and final bake.
How can I make it gluten-free?
Swap the all-purpose flour with a gluten-free blend, or use cornstarch as a thickening alternative.
Is it okay to use pre-shredded cheese?
You can, but freshly shredded cheese melts better and provides a creamier texture.
Want More Dinner Ideas with Comfort?
If this French Onion Beef Casserole made your dinner feel extra special, check out these cozy, hearty recipes too:
- Creamy Parmesan Pasta with Sautéed Garlic Butter Chicken for a rich, garlicky twist.
- Honey Garlic Ribs if you’re craving something sticky-sweet and savory.
- Ultimate Cheesy Ground Beef Melt for cheesy beefy goodness in every bite.
- Cream Cheese Chicken if you want creamy decadence in a skillet.
- Low Carb Greek Chicken Bowls for a lighter yet flavor-packed option.
Save This Pin + Share Your Results
📌 Save this recipe to your Pinterest comfort food board so you can revisit it on a cozy evening.
And tell me how yours turned out! Did you try a different cheese blend? Serve it over noodles instead of baking? I love seeing how you make these dishes your own. Drop your tips, questions, or twists in the comments!
French Onion Beef Casserole
- Prep Time: 20 minutes
- Cook Time: 3 hours
- Total Time: 3 hours 20 minutes
- Yield: Serves 6
- Category: Dinner
Description
This hearty casserole transforms the essence of French onion soup into a full, satisfying meal. With tender beef, caramelized onions, and layers of melty cheese, it’s cozy, comforting, and crowd-pleasing.
Ingredients
2.5 lbs beef chuck roast, cut into large chunks
3 large yellow onions, thinly sliced
3 cloves garlic, minced
3 cups beef broth
1 tbsp Worcestershire sauce
1 tsp dried thyme (or 1 tbsp fresh)
2 tbsp butter
2 tbsp olive oil
2 tbsp all-purpose flour
1 cup shredded Gruyère cheese
1 cup shredded mozzarella cheese
Salt and pepper to taste
Fresh parsley, chopped (for garnish)
Instructions
- Sear the beef: Season beef with salt and pepper. In a large pot, heat olive oil over medium-high and brown beef on all sides. Remove and set aside.
- Caramelize the onions: In the same pot, melt butter and add sliced onions. Cook over medium-low heat, stirring often, for 30–40 minutes until golden brown.
- Add aromatics: Stir in garlic, thyme, and flour. Cook for 1 minute.
- Make the sauce: Pour in beef broth and Worcestershire sauce, scraping the pan bottom. Simmer for a few minutes.
- Cook the beef: Return beef to the pot. Cover and simmer on low heat for 2 to 2.5 hours until beef is tender and can be shredded easily.
- Preheat oven: Set oven to 375°F.
- Assemble casserole: Shred beef and stir into onion mixture. Transfer to a baking dish and top with Gruyère and mozzarella.
- Bake: Bake uncovered for 15–20 minutes until cheese is melted and bubbly. Garnish with parsley and serve hot.
