Easy French Onion Soup

1/2 stick of unsalted butter
4 large onions, sliced
2 garlic cloves, chopped
2 bay leaves
2 fresh thyme sprigs
salt and pepper, lots of pepper
1 cup red wine
4 heaping tablespoons all-purpose flour
2 quarts good beef broth
1 baguette, sliced
1/2 pound grated Gruyere

Melt the stick of butter in a large pot over medium heat. Add the onions, garlic, bay leaves, thyme, and salt and pepper and cook until the onions are very soft and caramelized, about half an hour. Add the wine, bring to a boil, reduce the heat and simmer until the wine has evaporated and the onions are dry, about 5 minutes. Discard the bay leaves and thyme sprigs. Dust the onions with the flour and give them a stir. Turn the heat down to medium low. Add the beef broth, bring the soup back to a simmer, and cook for 10 minutes. Season with salt and pepper. When you're ready to eat, preheat the broiler. Arrange the baguette slices on a baking sheet in a single layer. Sprinkle the slices with the Gruyere and broil until bubbly and golden brown, 3 to 5 minutes. Ladle the soup in bowls and float several of the Gruyere croutons on top.