French Onion Cabbage Gratin Recipe
Prep Time
20 minutes
Cook Time
55 minutes
Total Time
1 hour 15 minutes
Servings
6–8
Ingredients
For the Cabbage
- 1 medium green cabbage, cored and sliced into wedges
- 1 tablespoon olive oil
- ½ teaspoon salt
- ¼ teaspoon black pepper
For the French Onion Mixture
- 3 large yellow onions, thinly sliced
- 3 tablespoons unsalted butter
- 1 tablespoon olive oil
- 2 cloves garlic, minced
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried thyme)
- ½ teaspoon salt
- ¼ teaspoon black pepper
For the Cream Sauce
- 1 cup heavy cream
- ½ cup beef broth or vegetable broth
- 1 teaspoon Dijon mustard
- ¼ teaspoon nutmeg (optional)
For the Topping
- 1½ cups shredded Gruyère cheese
- ½ cup grated Parmesan cheese
- ½ cup panko breadcrumbs
- 1 tablespoon melted butter
- Fresh parsley, chopped (for garnish)
Instructions
Step 1: Prepare the Cabbage
Preheat your oven to 400°F (200°C).
Arrange the cabbage wedges on a baking sheet. Drizzle with olive oil and season with salt and pepper.
Roast for 20–25 minutes until slightly tender and lightly browned around the edges.
Reduce oven temperature to 375°F (190°C).
Step 2: Caramelize the Onions
While the cabbage is roasting, heat the butter and olive oil in a large skillet over medium heat.
Add the sliced onions and cook slowly for 25–30 minutes, stirring occasionally, until deeply golden brown and caramelized.
Add the garlic, thyme, salt, and pepper. Cook for another minute until fragrant.
Step 3: Make the Cream Sauce
In a small bowl, whisk together:
- Heavy cream
- Broth
- Dijon mustard
- Nutmeg (if using)
Set aside.
Step 4: Assemble the Gratin
Lightly grease a 9×13-inch baking dish.
Arrange the roasted cabbage in an even layer.
Spread the caramelized onion mixture over the cabbage.
Pour the cream mixture evenly over the top.
Step 5: Add the Cheese Topping
Combine the Gruyère cheese and Parmesan cheese in a bowl.
Sprinkle evenly over the casserole.
In a separate small bowl, mix the panko breadcrumbs with melted butter and scatter over the cheese layer.
Step 6: Bake
Bake at 375°F (190°C) for 25–30 minutes, or until the sauce is bubbling and the top is golden brown.
For extra browning, broil for 2–3 minutes at the end of baking.
Step 7: Rest and Serve
Allow the gratin to rest for 5–10 minutes before serving.
Garnish with fresh parsley and serve warm.
Tips for the Best French Onion Cabbage Gratin
Be Patient with the Onions
Slow caramelization creates the rich, sweet flavor that makes this dish special.
Roast the Cabbage First
Roasting adds flavor and prevents the gratin from becoming watery.
Use Gruyère Cheese
Gruyère provides the classic French onion soup flavor and melts beautifully.
Don’t Skip the Breadcrumbs
They create a delicious crispy topping that contrasts perfectly with the creamy filling.
Let It Rest
Resting helps the sauce thicken and makes serving easier.
Variations
Bacon French Onion Gratin
Add 6 slices of cooked, crumbled bacon to the onion mixture.
Mushroom Cabbage Gratin
Sauté 8 ounces of sliced mushrooms with the onions.
Vegetarian Version
Use vegetable broth instead of beef broth.
Extra Cheesy Gratin
Add mozzarella or fontina cheese for an even richer topping.
Low-Carb Version
Omit the breadcrumbs and add extra cheese on top.
What to Serve with French Onion Cabbage Gratin
- Roast chicken
- Grilled steak
- Pork chops
- Meatloaf
- Baked salmon
- Holiday turkey
- Crusty bread
- Fresh green salad
Storage and Reheating
Refrigerator
Store leftovers in an airtight container for up to 4 days.
Freezer
Freeze for up to 2 months. Thaw overnight before reheating.
Reheating
Bake at 350°F (175°C) for 15–20 minutes or until heated through.
Why You’ll Love This Recipe
- Rich French onion flavor
- Creamy, cheesy, and comforting
- Perfect holiday or family dinner side dish
- Great use of simple ingredients
- Crispy golden topping
- Easy to prepare ahead of time
