Quick and Zesty Ina Garten's Onion & Fennel Soup Gratin Recipe - Worth Pinning

Ingredients

• 3 lb (1.36 kg) Spanish onions, halved and sliced ¼ inch thick
• 2 lb (907 g) fennel, tops and cores removed, sliced ¼ inch thick
• 8 cups (1.9 liters) canned beef broth
• 1½ cups (355 ml) dry white wine, such as Sauvignon Blanc
• ½ cup (118 ml) dry sherry
• ½ cup (118 ml) Cognac or brandy
• 4 tbsps (59 ml) unsalted butter
• ¼ cup (59 ml) olive oil
• 3 bay leaves
• 1 tbsp kosher salt
• 1½ tsps freshly ground black pepper
• 1 small sourdough or white French boule, crusts removed, sliced ½ inch thick, and toasted
• 4 to 6 oz (113 to 170 g) Gruyère cheese, grated