Katie Brown | Onion Soup with Croque Monsieur

Ingredients

• 5 medium-sized onions, thinly sliced
• 3 tablespoons butter
• 6 cups beef stock
• 1/2 teaspoon salt
• 1/8 teaspoon pepper
• Madeira wine or sherry
• French baguette, sliced into 1½-inch pieces on a diagonal, toasted
• 1/4 cup dijon mustard
• 4 slices of ham
• 1/4 cup grated gruyere cheese