This French Onion Soup is full of caramelized onions that have been simmered in red wine and beef broth, then put under the broiler to melt the cheese on top. This warm, comforting soup is perfect for cold days when you need to warm up!
Melt butter in a large pot over medium heat. Add the onions, garlic, bay leaves, thyme, salt, and pepper and cook until onions are soft and caramelized, about 30 minutes.
Add wine, bring to a boil then reduce heat to simmer, stirring occasionally, until the wine has evaporated and onions start to dry.
Discard bay leaves and thyme sprigs. Sprinkle flour over onions and cook stirring so the flour doesn't burn for about 10 minutes to cook out the raw flour taste.
Add the beef broth 1 cup at a time, stirring well while doing so. Bring the soup back to a boil. Reduce the heat and simmer another 10 minutes.
Place the soup in oven-safe bowls on a large baking sheet. Arrange bread slices on top of the soup and sprinkle with the cheese.