French Onion Soup Recipe | Saveur

Ingredients

• 3 large beef marrowbones (4½ lb.)
• 2 large carrots (12 oz.)
• 2 medium celery stalks (3 oz.)
• 1 large yellow onion (14½ oz.), unpeeled, halved
• 2 garlic cloves, unpeeled, smashed
• 2 small dried hot chiles, such as bird, árbol, or Kashmiri (optional)
• 1 small bunch Italian parsley
• 1 small bunch fresh thyme
• 2 bay leaves
• 1 Tbsp. black peppercorns
• 1 Tbsp. kosher salt
• 10 Tbsp. unsalted butter, divided
• 4 large yellow onions (3¾ lb.), peeled, halved lengthwise, and sliced ½ inch thick (11 cups)
• 1 tsp. sugar (optional)
• Kosher salt and freshly ground black pepper
• 1 fresh baguette, cut into twelve ½-inch slices
• 2 garlic cloves, peeled and halved
• 6 cups coarsely grated Gruyère cheese
• 2 cups coarsely grated Parmesan cheese
• 1 cup dry white wine
• ¼ cup dry sherry