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French Onion Lasagna

Savory French Onion Lasagna with Crispy Croutons Delight

A comforting French Onion Lasagna with layers of caramelized onions, cheese, and crispy croutons, perfect for any occasion.
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Prep Time 30 minutes
Cook Time 1 hour
Resting Time 10 minutes
Total Time 1 hour 40 minutes
Servings: 6 slices
Course: Dinner
Cuisine: French
Calories: 450
Ingredients Equipment Method Nutrition Notes

Ingredients
  

For the Lasagna
  • 9 sheets Lasagna Noodles Cook al dente for best results.
  • 2 cups Mozzarella Cheese Provides creaminess and melts beautifully.
  • 1 cup Gruyere Cheese A nutty flavor that deepens the dish.
For the Onion Mixture
  • 4 medium Yellow Onions Caramelize for sweetness and richness.
  • 4 tbsp Butter Essential for sautéing onions.
  • 3 tbsp Flour Used to create a roux for thickening.
  • 2 cups Beef Stock Richness to the onion mixture.
  • 1 tbsp Thyme Compliments the onion flavor.
  • 1 tbsp Worcestershire Sauce Deepens the umami profile.
  • 2 tbsp Balsamic Vinegar Balances flavors.
For the Béchamel Sauce
  • 2 cups Whole Milk Provides creaminess.
For the Croutons
  • 4 cups Sourdough Bread Adds unique crunch and flavor.
  • 2 tbsp Olive Oil Enhances flavor and crispness.
  • 1 tsp Garlic Powder Adds aromatic depth.

Equipment

  • baking dish
  • large pot
  • Skillet
  • Mixing bowl
  • Saucepan
  • Baking Sheet

Method
 

Preparation Steps
  1. Preheat your oven to 375°F (190°C) and grease a 10x14 or 9x13 baking dish.
  2. Toss cubed sourdough bread with olive oil, garlic powder, salt, and pepper, then bake for 16-20 minutes until golden and crispy.
  3. Boil salted water and cook the lasagna noodles until al dente, drain, and cool with cold water.
  4. In a skillet, melt butter and caramelize sliced onions over medium-low heat for 20-30 minutes.
  5. Add flour to the caramelized onions, then gradually add beef stock, thyme, Worcestershire sauce, and balsamic vinegar. Simmer until thickened for 5-7 minutes.
  6. In a separate saucepan, make a roux with butter and flour, then whisk in milk and Gruyere cheese until smooth.
  7. In the baking dish, layer onion sauce, noodles, croutons, and béchamel, repeating layers and finishing with noodles and cheese on top.
  8. Bake uncovered for 35-40 minutes until golden and bubbly. Allow to rest for 10 minutes before slicing.

Nutrition

Serving: 1sliceCalories: 450kcalCarbohydrates: 40gProtein: 20gFat: 25gSaturated Fat: 12gPolyunsaturated Fat: 1gMonounsaturated Fat: 3gCholesterol: 70mgSodium: 800mgPotassium: 350mgFiber: 2gSugar: 5gVitamin A: 600IUVitamin C: 10mgCalcium: 250mgIron: 3mg

Notes

Allow the lasagna to rest before slicing for better serving. Keep an eye on croutons while baking.

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