French Onion Ground Beef and Rice Casserole combines seasoned ground beef, tender rice, caramelized onions, and a creamy beef broth sauce, all topped with melted Gruyère and mozzarella cheese. The rich onion flavor is inspired by classic French onion soup, while the baked casserole makes it hearty enough for a family dinner.
This oven-baked meal is easy to prepare ahead and reheats well, making it a practical choice for busy weeknights or casual gatherings.
Recipe at a Glance
- Prep Time: 20 minutes
- Cook Time: 50 minutes
- Additional Time: 10 minutes
- Total Time: 1 hour 20 minutes
- Yield: One 9-by-13-inch casserole
- Servings: 6
- Difficulty: Easy
Why You’ll Love This Recipe
- Slowly caramelizing the onions develops deep, naturally sweet flavor without relying on onion soup mix.
- Cooking the rice before baking prevents uneven texture and ensures tender grains.
- Gruyère contributes the classic French onion flavor, while mozzarella creates a smooth, melty topping.
- A combination of beef broth and sour cream creates a creamy casserole without becoming overly heavy.
- Baking after assembly allows the flavors to blend while creating a golden cheese crust.
Equipment Needed
- 9-by-13-inch (23-by-33-cm) baking dish
- Large 12-inch (30-cm) skillet
- Medium saucepan with lid
- Chef’s knife
- Cutting board
- Wooden spoon
- Aluminum foil
- Instant-read thermometer
Ingredients You’ll Need
For the Rice
- 1 cup (190 g) uncooked long-grain white rice
- 2 cups (480 ml) water
- 1/2 teaspoon (3 g) fine sea salt
For the Beef Mixture
- 1 tablespoon (15 ml) olive oil
- 2 large yellow onions, about 1 pound (450 g), thinly sliced
- 1 pound (450 g) lean ground beef
- 3 medium garlic cloves (about 9 g), finely minced
- 1 teaspoon Worcestershire sauce
- 1 teaspoon dried thyme
- 1/2 teaspoon onion powder
- 1/2 teaspoon ground black pepper
- 1/2 teaspoon (3 g) fine sea salt
For the Sauce
- 1 tablespoon (8 g) all-purpose flour
- 1 1/2 cups (360 ml) low-sodium beef broth
- 1/2 cup (120 g) sour cream
- 1 teaspoon Dijon mustard
For the Topping
- 1 cup (110 g) shredded Gruyère cheese
- 1 cup (110 g) shredded low-moisture mozzarella cheese
- 1 tablespoon (4 g) chopped fresh parsley, optional
How to Make French Onion Ground Beef and Rice Casserole
Preheat the Oven
Position a rack in the center of the oven and preheat to 350°F (175°C). Lightly grease a 9-by-13-inch (23-by-33-cm) baking dish to prevent sticking and ensure easy cleanup after baking.
Cook the Rice
Combine the rice, water, and salt in a medium saucepan. Bring to a boil, reduce the heat to low, cover, and cook for 15 minutes. After cooking, remove from the heat and let it stand, covered, for 10 minutes before fluffing with a fork to achieve a light and fluffy texture.
Caramelize the Onions
Heat the olive oil in a large skillet over medium heat. Add the sliced onions and cook for 18 to 22 minutes, stirring often, until deeply golden and soft. If the onions begin browning too quickly, reduce the heat slightly and add 1 tablespoon of water to prevent burning.
Cook the Beef
Add the ground beef to the skillet with the onions. Cook for 6 to 8 minutes, breaking the meat into small crumbles, until no pink remains and it reaches 160°F (71°C). Drain excess grease if necessary to keep the casserole from becoming greasy.
Season the Mixture
Stir in the garlic, Worcestershire sauce, thyme, onion powder, black pepper, and salt. Cook for 30 seconds until fragrant, allowing the spices to bloom and enhance the overall flavor of the dish.
Prepare the Sauce
Sprinkle the flour over the beef mixture and stir for 1 minute. Gradually whisk in the beef broth. Simmer for 3 to 4 minutes until the mixture thickens slightly. Remove the skillet from the heat and stir in the sour cream and Dijon mustard until smooth, creating a creamy sauce.
Assemble the Casserole
Fold the cooked rice into the beef mixture until evenly combined. Spread the mixture into the prepared baking dish in an even layer, ensuring every bite has a balanced ratio of beef, rice, and sauce.
Add the Cheese
Sprinkle the Gruyère evenly over the casserole, followed by the mozzarella. This combination will create a deliciously gooey and flavorful topping.
Bake Covered
Cover the dish loosely with foil and bake for 20 minutes until heated throughout. This step helps to keep the casserole moist while it warms up.
Brown the Cheese
Remove the foil and continue baking for 10 to 12 minutes until the cheese is melted, bubbling, and lightly golden around the edges. This browning adds texture and flavor to the topping.
Rest Before Serving
Let the casserole rest for 10 minutes before serving. This allows the sauce to thicken slightly and makes serving easier, preventing the casserole from falling apart.
Garnish and Serve
Sprinkle with fresh parsley, if using, and serve hot. The garnish adds a touch of color and freshness to the dish.
Tips for Success
* Take the time to caramelize the onions fully for the richest flavor.
* Cook the rice just until tender so it does not become overly soft during baking.
* Drain excess grease from the beef before adding the sauce ingredients.
* Remove the skillet from the heat before stirring in the sour cream to reduce the chance of curdling.
* Let the casserole rest before serving so it slices more neatly.
* Use freshly shredded cheese for smoother melting than pre-shredded varieties.
Storage, Freezing, and Make-Ahead Instructions
Refrigerate leftovers within 2 hours in an airtight container for up to 4 days. Reheat covered in a 350°F (175°C) oven for 20 to 25 minutes, or microwave individual portions until they reach 165°F (74°C).
To freeze, cool the casserole completely, wrap tightly, and freeze for up to 2 months. Thaw overnight in the refrigerator before reheating. For make-ahead preparation, assemble the casserole without baking, cover tightly, and refrigerate for up to 24 hours. Let it stand at room temperature for 20 minutes before baking, adding about 5 extra minutes to the covered baking time if needed.
FAQ
Can I use instant rice?
Yes. Cook the instant rice according to its package directions before mixing it into the casserole. Do not add it uncooked.
Can I substitute another cheese?
Yes. Swiss, provolone, or white cheddar all melt well and pair nicely with the caramelized onion flavor, although Gruyère provides the most traditional French onion taste.
Why is my casserole watery?
The onions may not have cooked long enough to evaporate their moisture, or excess grease may not have been drained from the beef. Allow the sauce to simmer briefly before assembling the casserole.
Can I add mushrooms?
Yes. Add 8 ounces (225 g) of sliced mushrooms after the onions have softened and cook until their moisture evaporates before adding the beef.
What should I serve with French Onion Ground Beef and Rice Casserole?
A crisp green salad, steamed green beans, roasted broccoli, or roasted carrots balance the richness of the casserole well.
Ingredients
Method
- Preheat the Oven: Position a rack in the center of the oven and preheat to 350°F (175°C). Lightly grease a 9-by-13-inch (23-by-33-cm) baking dish to prevent sticking and ensure easy cleanup after baking.
- Cook the Rice: Combine the rice, water, and salt in a medium saucepan. Bring to a boil, reduce the heat to low, cover, and cook for 15 minutes. After cooking, remove from the heat and let it stand, covered, for 10 minutes before fluffing with a fork to achieve a light and fluffy texture.
- Caramelize the Onions: Heat the olive oil in a large skillet over medium heat. Add the sliced onions and cook for 18 to 22 minutes, stirring often, until deeply golden and soft. If the onions begin browning too quickly, reduce the heat slightly and add 1 tablespoon of water to prevent burning.
- Cook the Beef: Add the ground beef to the skillet with the onions. Cook for 6 to 8 minutes, breaking the meat into small crumbles, until no pink remains and it reaches 160°F (71°C). Drain excess grease if necessary to keep the casserole from becoming greasy.
- Season the Mixture: Stir in the garlic, Worcestershire sauce, thyme, onion powder, black pepper, and salt. Cook for 30 seconds until fragrant, allowing the spices to bloom and enhance the overall flavor of the dish.
- Prepare the Sauce: Sprinkle the flour over the beef mixture and stir for 1 minute. Gradually whisk in the beef broth. Simmer for 3 to 4 minutes until the mixture thickens slightly. Remove the skillet from the heat and stir in the sour cream and Dijon mustard until smooth, creating a creamy sauce.
- Assemble the Casserole: Fold the cooked rice into the beef mixture until evenly combined. Spread the mixture into the prepared baking dish in an even layer, ensuring every bite has a balanced ratio of beef, rice, and sauce.
- Add the Cheese: Sprinkle the Gruyère evenly over the casserole, followed by the mozzarella. This combination will create a deliciously gooey and flavorful topping.
- Bake Covered: Cover the dish loosely with foil and bake for 20 minutes until heated throughout. This step helps to keep the casserole moist while it warms up.
- Brown the Cheese: Remove the foil and continue baking for 10 to 12 minutes until the cheese is melted, bubbling, and lightly golden around the edges. This browning adds texture and flavor to the topping.
- Rest Before Serving: Let the casserole rest for 10 minutes before serving. This allows the sauce to thicken slightly and makes serving easier, preventing the casserole from falling apart.
- Garnish and Serve: Sprinkle with fresh parsley, if using, and serve hot. The garnish adds a touch of color and freshness to the dish.
