
Slice the onions thinly. Melt butter in a large pot over medium-low heat. Add onions and cook, stirring occasionally, until deeply caramelized (about 30-40 minutes). Add a pinch of salt and sugar to help the process.
Stir in flour and cook for 1 minute. Gradually whisk in beef broth, then add thyme, bay leaf, salt, and pepper. Bring to a simmer and cook for 15 minutes.
Preheat broiler. Slice baguette into 1-inch thick rounds and toast lightly.
Ladle soup into oven-safe bowls. Place a toasted baguette slice on top of each bowl and cover with grated Gruyère cheese.
Broil until cheese is melted and bubbly, about 2-3 minutes. Watch carefully to avoid burning.
Let cool slightly and serve immediately. Garnish with fresh parsley, if desired.
Enjoy this warm, comforting, and flavorful French Onion Soup!
A most agreeable soup. The flavors were well-balanced, and the cheese provided a delightful contrast in textures. I would certainly make it again.
A worthy meal for a warrior! The soup is hearty and flavorful, perfect after a long battle (or a long day at the office).
The onions took forever to caramelize, and the broth was a bit bland. Needs more seasoning. Disappointing.
Amazing! This soup is a culinary adventure. The Gruyère was so delicious, it's perfect. Definitely a recipe I'll treasure.
It was okay. The onions took a long time to caramelize, as expected. The flavor was a bit one-dimensional, perhaps needed a touch of acidity.