Place the onions, butter and thyme in a large pan and heat over low heat. Cook, stirring occasionally, until the onions are soft, translucent, and begin to caramelize, about 45 minutes to 1 hour. Just before the onions finish cooking, add the garlic and saute for another 30 seconds to 1 minute.
2 large onions, ¼ cup unsalted butter, 2 fresh thyme sprigs, 2 garlic cloves
Dust the mixture with flour and stir to combine. Cook for an additional 2 to 3 minutes.
2 to 3 tablespoons all-purpose flour
Add the wine and stir to combine. Cook for 5 to 7 minutes over low-medium heat, stirring occasionally. The liquid will reduce some but should not evaporate completely.
¾ cup red wine
After the alcohol evaporates from the wine, pour in the beef broth and add the bay leaves. Bring to a boil then reduce heat to a simmer. Cook for 15 to 20 minutes stirring occasionally. Taste, and add salt and pepper if desired.
32 ounces low-sodium beef broth, 2 bay leaves
While the soup simmers, place the cubed baguette onto a large baking sheet. Bake at 250°F for 10 to 15 minutes to warm and dry the bread slightly or at 350°F for crunchy bread.
Baguette
After the soup has simmered, ladle it into individual, oven-safe bowls. Place several toasted bread pieces into each bowl of soup, and top with shredded cheese (about 1 ounce each).
4 ounces Gruyere cheese
Place the bowls onto a baking sheet or in a baking dish for easy handling. Transfer the pan to the broiler, and broil for 4 to 5 minutes or until the cheese is melted and bubbly.
Enjoy immediately! Scroll up and see the post for tips, FAQs, and storage options.
Notes
*The calories listed are an approximation based on the ingredients in the recipe card and a serving size of 1 ¼ cups of soup. Actual calories will vary.*For more information, tips, and answers to frequently asked questions, please refer to the post.