- 1 tablespoon butter
- 1 tablespoon olive oil
- 3 cups sweet onion, sliced 1/4″ to 1/2″ thick
- 1/2 teaspoon thyme
- 1/4 teaspoon black pepper, coarse grind
- 1 bay leaf
- 2 tablespoons sherry
- 2 cups unsalted beef stock
- 4 slices french bread, sliced 1/2″ thick
- 1/4 cup shredded Gruyere
- 1 tablespoon Parmesan cheese
- Melt butter in skillet over medium heat.
- Add oil, onions, thyme, black pepper and bay leaf. Saute 10 minutes to soften onion.
- Add sherry. Cover and cook an additional 10 minutes until onions are limp.
- Add beef stock, bring soup to boil and simmer uncovered 15 minutes.
- While soup is simmering, prepare cheese toasts.
- Toast one side of french bread slices under oven broiler.
- Turn slices over, top with cheeses.
- Return to broiler to melt cheeses.
- Ladle soup into bowls and top with cheese toast.
- Serve immediately.