INGREDIENTS
- 3 tablespoons unsalted butter
- 2 tablespoons olive oil
- 2 pounds sweet onions, peeled, halved and sliced
- ¼ teaspoon salt
- 1 tablespoon Worcestershire sauce
- ¾ cup dry white wine (we use Pinot Grigio)
- 4 sprigs thyme
- 1 bay leaf
- 6 cups Beef Bone Broth
- ½ teaspoon ground black pepper
- 10-inch piece French baguette
- 8 ounces Gruyere cheese, grated
- 1 bunch fresh chives, finely chopped
DIRECTIONS
Caramelize the onions
Heat a 6-quart Dutch oven over medium heat. Add the olive oil, butter, and onions. Add salt. Sauté, stirring occasionally, until the onions are caramelized—about 45 minutes to an hour or more—making sure not to burn them. We’re looking for that signature deep brown color; be patient and eventually the onions will caramelize. When the onions are a few minutes from done, add the Worcestershire sauce and stir.
Deglaze and simmer
One the onions are caramelize and the bottom of the pan is starting to show some serious browned bits, go ahead and deglaze the pan with the white wine. After adding the wine, scrape the bottom of the pan with a flat wooden spoon. Stir to combine and let the mixture simmer until slightly reduced, about 1–2 minutes. Next, add the bay leaf, thyme, pepper, and beef bone broth. Stir to combine thoroughly and then bring to a boil. Once boiling, reduce heat and simmer, uncovered, for 30 minutes.
Make the croûte
Turn broiler on high. While the soup is simmering, slice the baguette diagonally into 1½-inch pieces. Place in a single layer on a rimmed baking sheet and broil until well-toasted and crispy, about 5 minutes. Remove from the oven and sprinkle Gruyere over them. Return to the broiler until the cheese is fully melted and just browning, about 2–3 minutes.
Garnish and serve
When the soup is done, ladle into bowls and top with croûte. Sprinkle with more Gruyere and garnish with fresh chives. Serve hot.
