French Onion Soup Casserole

  5.0 – 6 reviews  • Side Dish
This tasty casserole has all the flavors of French onion soup in the form of a comforting, scoopable side dish. Serve it alongside a roast for a special dinner, or with eggs at brunch. No matter what time of day you eat it, this crowd-pleaser is easy enough to become a standard in your meal planning.
Level: Easy
Total: 1 hr 40 min
Active: 40 min
Yield: 8 servings
Level: Easy
Total: 1 hr 40 min
Active: 40 min
Yield: 8 servings

Ingredients

  1. 5 tablespoons unsalted butter
  2. 2 tablespoons extra-virgin olive oil
  3. 5 large or 8 medium Vidalia onions, sliced
  4. Kosher salt and freshly ground black pepper
  5. 1 bay leaf
  6. 2 tablespoons all-purpose flour
  7. 1 cup whole milk
  8. 1/2 cup freshly grated Parmesan
  9. Dash freshly grated nutmeg
  10. 1 tablespoon balsamic vinegar
  11. 1 tablespoon Worcestershire sauce
  12. 2 1/2 cups beef broth
  13. 1 tablespoon chopped fresh thyme leaves
  14. 1 baguette, cut into 1/2-inch-thick slices
  15. 1 1/3 cups shredded mozzarella
  16. Chopped chives, for finishing

Instructions

  1. In a large pot, melt 2 tablespoons of the butter over medium heat. Add the oil and onions and toss well to coat the onions. Season with salt and pepper, add the bay leaf, and continue to cook, stirring occasionally, until the onions soften, 5 to 7 minutes.
  2. Reduce the heat to medium low and continue to cook, uncovered, stirring occasionally, until the onions begin to caramelize, 25 to 30 minutes longer. 
  3. While the onions cook, make the bechamel sauce: Melt 2 tablespoons of the remaining butter in a small saucepan over medium heat. Add the flour and whisk to combine. Whisk in the milk and bring to a simmer, whisking. When the sauce thickens, stir in the Parmesan and nutmeg. Season with salt and pepper. Set aside.  
  4. Preheat the oven to 400 degrees F. Grease a 9-by-13-inch baking dish with the remaining 1 tablespoon butter. 
  5. When the onions begin to caramelize, stir in the balsamic and Worcestershire and cook for 1 to 2 minutes more. Add the broth and thyme and bring to a simmer over medium heat. Remove and discard the bay leaf.  
  6. Transfer the onion mixture to the prepared dish. Arrange the baguette slices on top, then spoon a little bechamel sauce over each piece of bread. Top with the mozzarella. Bake until the cheese is melted and begins to brown and the filling is bubbling, 35 to 40 minutes.  
  7. Let cool for 5 to 10 minutes. Sprinkle with chives and serve. 

Nutrition Facts

Serving Size 1 of 12 servings
Calories 264
Total Fat 13 g
Saturated Fat 7 g
Carbohydrates 28 g
Dietary Fiber 2 g
Sugar 10 g
Protein 11 g
Cholesterol 29 mg
Sodium 617 mg
Serving Size 1 of 12 servings
Calories 264
Total Fat 13 g
Saturated Fat 7 g
Carbohydrates 28 g
Dietary Fiber 2 g
Sugar 10 g
Protein 11 g
Cholesterol 29 mg
Sodium 617 mg

Reviews

Steven Torres MD
Can you make a day in advance and refrigerate then bake?
Jennifer Long
My husband loves French onion soup and this hit the spot! He even passed the recipe on to his best friend since he liked it so much.
Lauren Chavez
This was really good! Made it for my family and my kids wanted seconds. 5 stars!
Monique Perry
Delicious!

 

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