Ever order French onion soup at a recipe only to get a bowl with so much cheese you can’t tell whether you ordered soup or a grilled cheese sandwich? Yeah, me too. That’s why I love to make slow cooker French onion soup at home. I can control the cheese. I like mine on top of lightly crusted sliced baguettes. Like crunchy cheese croutons. Perfect on a cold day, this soup is packed with fantastic onion flavor.
I like to add a bit of beef base to my slow cooker French onion soup to give it just a bit more beefy flavor. Although it’s completely optional if you use a good homemade beef broth. I felt it could use a little help in the beefiness flavor department.
Also try my slow cooker spicy kielbasa cabbage soup.
Slow Cooker French Onion Soup
- 6 tablespoons unsalted butter
- 4 large yellow onions sliced thin, rings separated
- 1 tablespoon sugar
- 2 cloves garlic minced
- 1/2 cup cooking sherry
- 7 cups beef broth
- 1 tablespoon beef base optional
- 1 teaspoon kosher salt
- 1/4 teaspoon dried thyme
- 1 bay leaf
- 8 slices of French bread or 16 slices of a thin baguette
- A mix of shredded Gruyere Emmental, Parmesan and Mozzarella cheeses
- Melt the butter in a large pot or Dutch oven over medium-high heat.
- Add the onions and saute about 10 minutes or until translucent, stirring often.
- Sprinkle with the sugar, stir and reduce heat to medium. Cook 30-40 minutes or until soft and lightly caramelized.
- Add the garlic, stir and cook 2 more minutes.
- Stir in the sherry and cook until evaporated, stirring and scraping up any yummy bits on the bottom of the pot.
- Transfer the onions to a lightly greased slow cooker on low.
- Stir in the broth, beef base, salt, thyme and bay leave.
- Cover and cook 8 hours.
- Place bread pieces under the broiler to get lightly browned. Sprinkle with cheese and place back under the broiler until the cheese is melted.
- Serve soup in bowls topped with a slice of the cheese bread (or 2 slices if using a small baguette).