French Onion Soup with Grilled Cheese Croutons
- ½ cup (1 stick) unsalted butter, plus more, at room temperature, for grilled cheese
- 6 yellow onions, sliced
- 1 bay leaf
- 4 sprigs thyme
- Kosher salt and freshly ground pepper
- 1 baguette, sliced on the diagonal 1/3-inch-thick
- 8 oz Gruyère cheese, grated
- ½ cup port
- 2 (32-oz) boxes low-sodium beef broth
Preheat oven to 400°F. Melt butter in a large Dutch oven over medium heat. Add onions and herbs, season with salt, and cook, stirring occasionally, until golden and caramelized, about 35 minutes.
Meanwhile, butter baguette slices on one side, then arrange half of them on a parchment-lined baking sheet, buttered side down. Top each with a generous pinch of Gruyère. Set remaining baguette slices into place on top of cheese, buttered side up, to make 12 small sandwiches. Season tops with salt.
Once onions are caramelized, add port, bring to a boil, then reduce heat to medium-low and simmer, stirring up any browned bits, until the port is almost evaporated, 8 to 10 minutes. Add beef broth, return to a simmer, and cook 15 minutes. Season with salt and pepper.
Meanwhile, during last 10 minutes of cooking, bake sandwiches in oven until cheese is melted, about 5 minutes. Flip and bake 5 minutes more. Put 1 grilled cheese in each of 6 bowls. Pour soup over and top each with 1 more grilled cheese.
Gruyère is one of our favorite cheeses: It’s full-flavored and melts extremely well. But it can be expensive. For a less pricey alternative, try fontina in this recipe instead.
Serves 6. Per serving: 530 cal, 28g carbs, 18g protein, 36g fat, 105mg chol, 410mg sodium, 3g fiber