INGREDIENTS

• 2 tablespoons unsalted butter, chopped
• 1 tablespoon olive oil
• 3 large sweet onions, thinly sliced
• ½ teaspoon salt, plus more to taste
• Freshly ground black pepper to taste
• 2 teaspoons dark brown sugar
• 2 teaspoons Worcestershire sauce
• 3 sprigs fresh thyme
• 1 bay leaf
• ½ cup dry sherry
• 8 cups good quality beef stock, warmed
• 8-16 slices French bread (depending on thickness of bread loaf)
• 2 cups grated Gruyère cheese
• Flaky sea salt, for serving

HOW TO MAKE IT

1. Place a 5.5-quart STAUB Dutch oven on the STAUB Multicooker and choose the Browning setting. Set the time to 20 minutes.
2. When done preheating, add the butter and oil. When butter is melted add the onions, ½ teaspoon salt, and a few grinds of pepper. Cook, stirring for about 10 minutes, until the onions are softening and beginning to color. Add the sugar and Worcestershire sauce and cook for another 5 minutes, until very soft and darker in color.
3. Choose the Slow Cook Low setting, set the time to 3 hours and continue stirring the onions for a minute while the pan cools down. Add the thyme sprigs and bay leaf, cover, and slow cook to intensify flavors and fully soften onions.
4. Choose the Slow Cook High setting. When preheated, add the sherry and stock, and cook, covered, for another 1 to 2 hours. The longer you cook the soup, the more intense the flavors will become.
5. Preheat a conventional oven to Broil. Remove bay leaf and thyme sprigs from soup and spoon into oven-proof bowls placed on an oven tray. Top each bowl with bread and cheese and broil for 1 to 2 minutes, keeping an eye on the bowls to make sure the cheese and bread don’t burn. When the cheese is melted, bubbly, and browned in spots, remove from the oven, and serve sprinkled with flaky sea salt.