Main dish

Onion Soup Flavored Casserole

10 m
2 h 5 m
Ready in:
2 h 15 m
Cook a bigger batch of cheesy onion soup with this Onion Soup Casserole recipe!
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Servings: 6
Unsalted butter
3 tbsps
Olive oil
2 tbsps
Medium onions
4, sliced
2 stalks, peeled, sliced
Kosher salt
 to taste
Fresh ground black pepper
to taste
Bay leaves 
Fresh thyme leaves
1 tsp + 2 sprigs
1 tbsp
Low-sodium beef broth
1 cup
Dry white wine
½ cup
Baguette, sliced 
Gruyere cheese
2 cups (4 oz), shredded  
  1. In a large pot, melt butter together with olive oil. Add onions and celery, season with salt and pepper, add bay leaves and thyme sprigs. Cook uncovered, stirring occasionally, for about 45 minutes until liquid evaporates and onions become soft and golden brown. If the onions do not brown in 45 minutes, increase the heat slightly and cook for a few minutes longer.
  2. Stir in the flour, cook for a minute. Pour the broth and wine into the pot; simmer for 2 minutes (the liquids should evaporate almost completely). Remove from heat; let cool slightly; remove the herbs (you can complete this stage up to 2 days ahead and refrigerate until it’s time to cook the casserole). 
  3. Preheat the oven to 350 F/180 C/Gas Mark 4. Bake the baguette slices on a baking sheet until toasted slightly (2-3 minutes per side). Let the bread cool.
  4. Place the bread slices, slightly overlapping, into the baking dish. Top with the onion mixture. Cover with the remaining bread. Sprinkle with grated Gruyere.
  5. Cover with foil and bake for about 40 minutes. Remove foil; switch to broil and cook until golden. Serve hot, sprinkled with thyme leaves.
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