Ingredients:

  • 4 large yellow onions, thinly sliced pole-to-pole
  • 4 Tbsp unsalted butter
  • 1 Tbsp olive oil
  • 1 tsp brown sugar (optional)
  • 2 Tbsp all-purpose flour
  • 1/2 cup dry white wine (or dry sherry)
  • 6 cups quality beef broth/stock (low sodium preferred)
  • 4 sprigs fresh thyme
  • 1 large bay leaf
  • 1 tsp Worcestershire sauce
  • Salt and freshly ground black pepper to taste
  • 1 loaf baguette, sliced thickly (about ¾ inch)
  • 6 oz Gruyère cheese, shredded or sliced thinly

Instructions:

  1. Melt butter and oil in a large, heavy-bottomed Dutch oven over medium heat. Add all sliced onions and a pinch of salt. Cook gently for 15 minutes, stirring occasionally, until softened and translucent.
  2. Reduce heat to medium-low. Continue cooking onions for 60–75 minutes, stirring every 5–10 minutes initially, then every 2–3 minutes as they darken. The goal is a deep, rich mahogany brown colour, scraping up any fond from the bottom.
  3. Stir in the flour and cook for 1 minute. Pour in the white wine and scrape the bottom vigorously to lift all the flavourful brown bits. Let the wine reduce by half (about 3 minutes).
  4. Pour in the beef broth. Add thyme sprigs, bay leaf, and Worcestershire sauce. Bring to a gentle simmer, then reduce heat, cover partially, and cook for 20 minutes to let flavours meld. Remove herbs and adjust seasoning.
  5. While soup simmers, lightly toast baguette slices in the oven until just golden and dry.
  6. Ladle hot soup into oven-safe crocks. Top each bowl with 1-2 toasted baguette slices. Generously cover the bread with Gruyère cheese, ensuring edges are covered.
  7. Place crocks on a sturdy baking sheet and broil on the top rack for 2–4 minutes, watching constantly, until the cheese is melted, bubbling, and beautifully browned. Serve immediately.