Description
Hearty cheese-laden french onion soup casserole brings classic French flavors to comfort cuisine. Rich caramelized onions and melted gruyère create a soul-warming dish you’ll crave during chilly evenings.
Ingredients
Scale
- 1.36 kg (5 medium) vidalia onions, thinly sliced
- 16 oz (1) baguette, thinly sliced
- 8 oz (226 g) gruyère cheese, shredded (about 2 cups)
- 3 cups (710 ml) reduced-sodium beef broth
- ½ cup (120 ml) sherry
- ¼ cup (56 g) unsalted butter
- 2 tsps kosher salt
- ½ tsp black pepper
- 3 thyme sprigs
- 2 flat-leaf parsley sprigs
- 2 bay leaves
- ⅓ cup all-purpose flour
- 1 tsp fresh thyme leaves
Instructions
- Caramelization: Melt butter in a Dutch oven over medium-low heat. Incorporate sliced onions, seasonings, and herb sprigs. Tenderly cook for one hour, transforming onions into a deep golden-amber hue, stirring occasionally to prevent scorching.
- Bread Preparation: Heat oven to 350°F. Arrange baguette slices on a baking sheet, creating a uniform layer. Toast for 12 minutes until crisp and lightly golden, then reserve for layering.
- Flavor Intensification: Remove herb sprigs from caramelized onions. Dust with flour, whisking continuously to create a rich, smooth base without burning. This step develops complex flavor foundations.
- Liquid Integration: Stream beef broth and dry sherry into the onion mixture. Elevate heat, bringing contents to a vigorous boil while stirring. Allow sauce to thicken and develop robust depth, approximately 2-3 minutes.
- Casserole Construction: Grease a 13 x 9-inch baking dish. Craft initial bread foundation by evenly distributing half the toasted baguette slices across the bottom, creating a sturdy base.
- Layering Technique: Spread onion-broth mixture uniformly over bread layer. Crown with remaining baguette slices, establishing a harmonious two-tier structure.
- Cheese Coverage: Lavishly blanket the surface with shredded Gruyère or Swiss cheese. Encase dish completely with aluminum foil to retain moisture and promote even heating.
- Baking Process: Bake for 30 minutes. Remove foil, transition oven to broil. Broil 3 minutes until cheese transforms into a bubbling, golden-brown masterpiece with crispy edges.
- Finishing Touch: Sprinkle freshly chopped thyme leaves across the surface. Rest casserole for 5 minutes, allowing layers to stabilize and flavors to harmonize before serving.
Notes
- Slow Caramelize Onions: Take time to develop deep, rich flavor by cooking onions on medium-low heat for a full hour, stirring occasionally to prevent burning.
- Toast Bread Carefully: Perfectly crisp baguette slices ensure a crunchy texture that won’t become soggy when mixed with the onion broth.
- Control Cheese Melting: Watch closely during broiling to achieve golden, bubbly cheese without burning the top layer of the casserole.
- Rest Before Serving: Allow 5 minutes of cooling time to help layers set and make serving easier, preventing the casserole from falling apart.
- Prep Time: 1 hour 20 minutes
- Cook Time: 45 minutes
- Category: Dinner, Appetizer
- Method: Baking
- Cuisine: French
Nutrition
- Serving Size: 9
- Calories: 310
- Sugar: 4 g
- Sodium: 600 mg
- Fat: 14 g
- Saturated Fat: 8 g
- Unsaturated Fat: 6 g
- Trans Fat: 0 g
- Carbohydrates: 36 g
- Fiber: 2 g
- Protein: 10 g
- Cholesterol: 30 mg