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.
Why This Recipe Works
- 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 List
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
Ingredient Notes and Substitutions
- Yellow onions: Yellow onions caramelize beautifully and create the signature sweet, savory flavor. Sweet onions may be substituted for a slightly milder casserole.
- Ground beef: Lean ground beef keeps the casserole flavorful without producing excessive grease. Ground turkey can replace it, though the finished dish will have a lighter flavor.
- Gruyère: cheese: Gruyère provides the classic flavor associated with French onion soup. Swiss cheese is the closest substitute, while provolone offers a milder alternative.
- Long-grain white rice: This rice stays fluffy after baking. Cooked brown rice may be substituted, although it has a firmer texture and nuttier flavor.
- Sour cream: Sour cream adds creaminess and slight tang. Plain full-fat Greek yogurt can replace it with a slightly tangier finish.
Step-by-Step Instructions
Step 1: 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.
Step 2: 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. Remove from the heat and let it stand, covered, for 10 minutes before fluffing with a fork.
Step 3: 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.
Step 4: 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.
Step 5: Season the mixture
Stir in the garlic, Worcestershire sauce, thyme, onion powder, black pepper, and salt. Cook for 30 seconds until fragrant.
Step 6: 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.
Step 7: 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.
Step 8: Add the cheese
Sprinkle the Gruyère evenly over the casserole, followed by the mozzarella.
Step 9: Bake covered
Cover the dish loosely with foil and bake for 20 minutes until heated throughout.
Step 10: 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.
Step 11: Rest before serving
Let the casserole rest for 10 minutes before serving. This allows the sauce to thicken slightly and makes serving easier.
Step 12: Garnish and serve
Sprinkle with fresh parsley, if using, and serve hot.
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
- 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.
- 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. Remove from the heat and let it stand, covered, for 10 minutes before fluffing with a fork.
- 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.
- 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.
- Stir in the garlic, Worcestershire sauce, thyme, onion powder, black pepper, and salt. Cook for 30 seconds until fragrant.
- 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.
- Fold the cooked rice into the beef mixture until evenly combined. Spread the mixture into the prepared baking dish in an even layer.
- Sprinkle the Gruyère evenly over the casserole, followed by the mozzarella.
- Cover the dish loosely with foil and bake for 20 minutes until heated throughout.
- Remove the foil and continue baking for 10 to 12 minutes until the cheese is melted, bubbling, and lightly golden around the edges.
- Let the casserole rest for 10 minutes before serving. This allows the sauce to thicken slightly and makes serving easier.
- Sprinkle with fresh parsley, if using, and serve hot.
