Ingredients:
- lbs Yellow Onions, thinly sliced
- Tbsp Unsalted Butter
- Tbsp Olive Oil
- tsp Kosher Salt, plus more to taste
- Tbsp All-Purpose Flour
- /2 cup Dry Sherry or Dry White Wine
- cups High-quality, low-sodium Beef Broth or Stock
- sprigs Fresh Thyme
- large Bay Leaf
- Freshly Ground Black Pepper, to taste
- thick slices Baguette or Stale Country Loaf
- 1/2 cups Shredded Gruyère Cheese
- Tbsp Fresh Parsley, chopped (for garnish)
Instructions:
- Melt butter and oil in a large, heavy-bottomed Dutch oven over medium-low heat. Add onions and 1 tsp salt. Cook slowly, stirring every 10-15 minutes, for 45–60 minutes until the onions are deep, dark brown (mahogany colour).
- Sprinkle flour over the caramelised onions and cook for 2 minutes, stirring constantly. Pour in sherry or wine, scraping up all the browned bits (the fonds) stuck to the bottom of the pot. Cook until the liquid has mostly evaporated.
- Add the beef stock, thyme bundle, and bay leaf. Bring the mixture to a gentle simmer. Partially cover and cook for 30–40 minutes, allowing the flavours to meld. Remove and discard the thyme and bay leaf. Adjust seasoning with salt and pepper to taste.
- While the soup simmers, lightly toast the baguette slices until dried out but not hard (about 10 minutes in a 350°F/175°C oven).
- Ladle the hot soup into 4 oven-safe crocks, ensuring each bowl has a good amount of onion. Float 1-2 toasted baguette slices on top of the liquid in each bowl. Generously cover the bread completely with shredded Gruyère cheese.
- Place the crocks on a sturdy baking sheet. Broil on a high rack until the cheese is bubbly, melted, and deeply golden brown (watch constantly, as this takes only 1–3 minutes).
- Serve immediately, garnished with fresh chopped parsley. Warn guests that the bowls will be extremely hot.