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.

Servings: 6 servings

Author:

Prep Time
1 hour

Cook Time
21 minutes

Total Time
22 minutes

Course:

Soup

Cuisine:

French

Keywords:

slow cooker Onions

🧂 Ingredients

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
2 cups grated Gruyère cheese

(about 1/3 cup per bowl)

Instructions

1 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.
2 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.
3 Preheat your oven to 425°F. Slice the baguette into pieces about 1 inch thick,
using 2-3 slices for each serving.
4 Arrange the baguette slices on a sheet pan and bake for about 7-8 minutes until
they are golden brown and toasted.
5 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.
6 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.