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Classic French Onion Soup with Gruyère Crouton inspired by The Hungry I
Inspired by The Hungry I

Classic French Onion Soup with Gruyère Crouton

Appetizer
This hearty French onion soup features deeply caramelized onions in a rich, savory broth. The slow cooking process transforms simple ingredients into a complex soup with layers of flavor. Topped with a crusty baguette slice and melted Gruyère cheese, this appetizer bridges the gap between soup and a satisfying first course.
Prep Time 15 mins
Cook Time 75 mins
Total Time 90 mins
Servings 6

Ingredients

  • 2 lbs Yellow onions (Thinly sliced)
  • 3 tbsp Unsalted butter
  • 1 tbsp Olive oil
  • 1 tsp Granulated sugar (To help with caramelization)
  • 3 tbsp All-purpose flour
  • 6 cups Beef stock (Homemade preferred or low-sodium)
  • 1/2 cup Dry white wine
  • 1 whole Bay leaf
  • 2 sprigs Fresh thyme
  • 2 tbsp Cognac or brandy (Optional)
  • 1 tsp Sea salt (To taste)
  • 1/4 tsp Fresh ground black pepper (To taste)
  • 1 whole Baguette (Cut into 1-inch thick slices)
  • 8 oz Gruyère cheese (Grated)

Tools You'll Need

  • Large Dutch oven or heavy-bottomed pot
  • Wooden spoon
  • Ovenproof soup bowls or crocks
  • Baking sheet
  • Ladle

Chef's Tip

The key to exceptional French onion soup is properly caramelizing the onions, which should take at least 45 minutes. Don't rush this step—the slow cooking process develops the deep flavor that makes this soup special.

Instructions

  1. In a large heavy-bottomed pot or Dutch oven, melt butter with olive oil over medium heat.
  2. Add sliced onions and sugar, stir to coat. Cook on medium-low heat for 45-50 minutes, stirring occasionally, until onions are deeply caramelized to a rich golden brown.
  3. Add flour to the caramelized onions and cook for 3 minutes, stirring constantly.
  4. Slowly add wine, scraping the bottom of the pot to release any browned bits.
  5. Add beef stock, bay leaf, and thyme sprigs. Bring to a simmer and cook for 20-30 minutes.
  6. If using cognac, add it during the last 5 minutes of cooking.
  7. Remove bay leaf and thyme sprigs. Season with salt and pepper to taste.
  8. Preheat broiler. Place ovenproof soup bowls on a baking sheet.
  9. Toast baguette slices until lightly golden on both sides.
  10. Ladle soup into bowls, place a toasted baguette slice on top of each, and cover generously with grated Gruyère.
  11. Place under broiler until cheese is melted, bubbly, and starting to brown, about 2-3 minutes.

Plating

Serve in individual ovenproof crocks or soup bowls with the melted cheese bubbling on top. Provide a small plate underneath for serving, as the bowls will be very hot. Garnish with a small sprig of fresh thyme if desired.

Storage & Reheating

The soup base (without bread and cheese) can be refrigerated for up to 3 days or frozen for up to 1 month. Reheat gently on the stovetop, then add the bread and cheese topping just before serving.

About This Recipe

This recipe recreates the hearty French Onion Soup that was a staple at The Hungry I, a longstanding French restaurant in Boston's Beacon Hill. The traditional approach with properly caramelized onions and bubbling Gruyère creates a comforting appetizer that balances rustic bistro fare with elegant presentation.

How did it turn out?

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