Classic French Onion Soup with Potatoes

1In a large heavy-bottomed pot or Dutch oven, heat the butter and olive oil (2 tablespoons) over medium heat until melted and shimmering.

2Add the sliced onions and stir to coat them in the butter and oil. Cook slowly, stirring occasionally, for about 30-40 minutes until the onions are deeply golden brown and caramelized. Sprinkle the sugar over the onions after 10 minutes to help with caramelization.

3Add the minced garlic (4 cloves) and cook for another 1-2 minutes until fragrant, stirring frequently to prevent burning.

4Pour in the white wine (if using) to deglaze the pot, scraping up any browned bits from the bottom. Let it simmer until mostly evaporated, about 3-4 minutes.

5Add the diced potatoes, beef broth (8 cups), bay leaves (2), and thyme sprigs to the pot. Increase the heat to bring the soup to a gentle boil, then reduce to a simmer.

6Simmer the soup uncovered for 20-25 minutes, or until the potatoes are tender when pierced with a fork.

7Remove the bay leaves (2) and thyme sprigs. Season the soup with salt and freshly ground black pepper to taste.

8While the soup simmers, preheat the oven broiler. Arrange the baguette (1) slices on a baking sheet and toast them under the broiler until golden brown, about 1-2 minutes per side. Remove from oven.

9Ladle the hot soup into oven-safe bowls or crocks, ensuring a good amount of onions and potatoes in each.

10Place one or two toasted baguette (1) slices on top of each bowl of soup. Generously sprinkle grated Gruyère cheese (2 cups) over the bread, covering it completely.

11Place the bowls on a baking sheet and broil in the oven until the cheese is melted, bubbly, and golden brown, about 3-5 minutes. Watch carefully to prevent burning.

12Remove from oven and let cool slightly. Garnish with chopped fresh parsley before serving.