Bruce's Favorite French Onion Soup

Bruce’s favorite French onion soup is the home-cook’s take on the bistro standard, with two smart twists: a generous pour of brandy for a warmer backbone, and a mix of beef and chicken bouillon for a more rounded broth than beef stock alone. Spanish onions cook gently in butter until silky soft, then simmer for 90 minutes in the spiked broth so all the flavors weld together.

The key to the toppings is generosity. A thin scatter of croutons and cheese gives you a flat, sad disc on top. A heaped pile creates that bubbly, blistered, mahogany crust that makes French onion soup worth ordering. Mixing mozzarella with Swiss is the move. The mozzarella melts into long, gooey strings while the Swiss adds the proper nutty, savory flavor.

Pro Tips

• Slice the onions thin and even for uniform cooking. Thick chunks won’t soften through and you’ll end up with crunchy bites.
• Dissolve bouillon cubes in a measuring cup of boiling water before adding to the pot. Whole cubes settle to the bottom and never fully dissolve.
• Use oven-safe French onion soup crocks or thick-walled ramekins. Thin bowls can crack from the temperature swing.
• Place crocks on a sheet pan when broiling. Cheese drips will scorch on the bottom of the oven and smoke up the kitchen.

Variations

• Swap brandy for cognac, sherry, or port for slightly different finishing flavors.
• Add a tablespoon of fresh thyme leaves with the bouillon for a more traditional French herb profile.
• Use traditional Gruyère instead of mozzarella for a sharper, more authentically French cheese cap.