- 1/4 cup butter
- 2 onions, halved and thinly sliced
- 1 pint heavy cream
- 2 cups beef broth
- salt and pepper, to taste
- 3 slices French bread
- 3 slices provolone cheese
- 3 slices Swiss cheese
- Preheat oven to broiler setting.
- Melt butter in a saucepan over medium heat. Add onions and cook until softened, 5 to 8 minutes. Stir in the heavy cream and beef broth. Bring to a boil, then reduce heat to low and simmer, loosely covered, for 20 minutes. Season with salt and pepper, to taste.
- Top each slice of bread with one slice of provolone and one slice of Swiss cheese; place on a cookie sheet. Broil on top oven rack until the cheese browns and the edges of the bread are crispy, 3 to 5 minutes.
- To serve, ladle soup into 3 bowls and top with one slice of the cheese-topped bread.