Diner-Style French Onion Soup

Ingredients

• 5 pounds yellow onions, halved and sliced thin
• 6 tablespoons unsalted butter
• 2 tablespoons vegetable oil
• 1 1/2 teaspoons salt
• 1 teaspoon sugar
• 3 tablespoons all-purpose flour
• 1/2 cup dry sherry
• 1/2 cup dry white wine
• 8 cups beef broth
• 2 cups chicken broth
• 4 sprigs fresh thyme
• 2 bay leaves
• 1 tablespoon Worcestershire sauce
• 1 teaspoon black pepper
• 6 thick slices sturdy country bread
• 8 ounces Gruyere or Swiss cheese, shredded
• 4 ounces provolone, shredded

Before you cook

• Halve the onions through the root and slice them thin, pole to pole.
• Shred both cheeses and toss them together in one bowl.
• Cut the bread into slices that will fit inside your soup crocks.

Steps

1. Melt the butter with the oil in a very large heavy pot over medium heat.
2. Add all the sliced onions with the salt and sugar, piling them high above the rim if you must.
3. Cover the pot and cook for 20 minutes, until the onions collapse and release a pool of liquid.
4. Uncover the pot and raise the heat to medium.
5. Cook the onions for 50 to 60 minutes, stirring every 5 minutes and scraping the brown film off the bottom each time.
6. Keep going until the onions are jammy, glossy and the color of dark caramel.
7. Sprinkle the flour over the onions and stir for 2 minutes.
8. Pour in the sherry and white wine and scrape the pot bottom clean.
9. Boil the wine for 3 minutes.
10. Add the beef broth, chicken broth, thyme sprigs, bay leaves, Worcestershire and black pepper.
11. Simmer the soup uncovered for 30 minutes and taste for salt.
12. Toast the bread slices on a sheet pan under the broiler until dry and crisp on both sides.
13. Set six oven-safe crocks on a sheet pan and ladle the soup in, leaving an inch at the top.
14. Float a toast slice on each and pile the mixed cheese over it, letting some spill onto the rim.
15. Broil the crocks 6 inches from the element for 4 minutes, until the cheese blisters and browns.
16. Let the crocks sit for 3 minutes before serving, since they will be dangerously hot.