Slow Cooker French Onion Soup
This slow cooker French onion soup is a cozy dish filled with rich flavors that will warm your soul. With caramelized onions, savory broth, and melted Gruyère cheese, it’s a perfect meal for chilly weekends.
Equipment
- slow cooker
- oven
- sheet pan
Ingredients
For the Soup:
- 3 pounds yellow onions peeled and sliced into quarter-moons
- 2 tablespoons unsalted butter melted
- 2 tablespoons olive oil
- 2 teaspoons kosher or sea salt plus more to taste
- 8 cups reduced-sodium beef broth (64 ounces)
- 2 tablespoons balsamic vinegar
- 3 tablespoons cognac or brandy optional
For Serving:
- 2 cups grated Gruyère cheese (about 1/3 cup per bowl)
Instructions
For the Soup:
- Combine the sliced onions, olive oil, melted butter, salт, and optional black pepper in the slow cooker. Set it to cook on low for approximately 14 hours, stirring a couple of times if you can.
- Once the onions are caramelized, add in the beef broth, balsamic vinegar, and cognac or brandy. Mix well and continue to cook on low for another 7-8 hours.
For Serving:
- Preheat your oven to 425°F. Slice the baguette into pieces about 1 inch thick, using 2-3 slices for each serving.
- Arrange the baguette slices on a sheet pan and bake for about 7-8 minutes until they are golden brown and toasted.
- To serve, ladle the soup into bowls. Place 2-3 slices of the toasted baguette on top of each bowl, then sprinkle each with 1/3 cup of Gruyère cheese. To make serving easier, place the bowls on a sheet pan and transfer them to the oven. Bake for around 10 minutes, or until the cheese is melted and bubbly.
- Be cautious as you serve these hot bowls of soup. Enjoy your heartwarming soup, and consider pairing it with a fresh salad for a delightful side.