A Very Rich French Onion Soup

I love a good French Onion Soup, and I'm always trying to perfect the recipe.  Here's my latest . . .

1 stick of butter
4 medium white onions (sliced thinly)
2 garlic cloves (minced)
2 bay leaves
1/2 tsp thyme
Kosher salt and freshly ground pepper to taste
1 cup of red wine
3 Tbsp Worcestershire Sauce
3 heaping Tbsp flour
8 cups beef broth
1 loaf French bread
1/2 lb mozzarella cheese (cut into small cubes)

Melt the stick of butter in a large 12" skillet over medium heat.  Slice the onions and mince the garlic.   Add to the butter with the bay leaves and thyme.  Add salt and pepper and cook until the onions are caramelized (about 25 minutes).

Add the wine, and bring to a boil.  Reduce the heat and simmer until the wine has evaporated (about 5 minutes).  Add the flour to the onions and cook while stirring for about 10 minutes.  Add the beef broth while stirring constantly.  Add the Worcestershire sauce and bring to a simmer.  Cook for about 20 minutes, stirring frequently.  Taste and season with salt and pepper as desired.

While the soup simmers, slice the French bread into 1" cubes.  Toss them into a skillet and toast in a 400 degree oven for about 10 minutes or until crunchy.

To serve, place a handful of toasted bread cubes and several cheese cubes in the bottom of a soup bowl.  Spoon the simmering soup into the bowl and serve immediately.