Slow Cooker French Onion Soup
French Onion Soup made easy in the slow cooker. Caramelized onions in a rich broth, topped with toasted baguette and melty gruyère cheese.
Ingredients
- 4 yellow onions, thinly sliced
- ¼ cup butter
- 1 tablespoon brown sugar
- 1 tablespoon tamari
- ½ teaspoon dried thyme
- ½ teaspoon cracked black pepper
- ½ teaspoon salt
- 6 cups mushroom broth
- ½ baguette, sliced
- 1 cup gruyère cheese, shredded
Instructions
- In a slow cooker pot, add the onions, butter, brown sugar, tamari, thyme, pepper, and salt. Cover and set to slow cook on “Low” for 8-10 hours to caramelize the onions.
- After the onions have cooked down and caramelized, add the broth and stir well, scraping up any browned bits from the bottom of the pot. Cook for 5 minutes, until the broth is heated through.
- Meanwhile, toast 4 baguette slices until golden brown and crispy, like a crouton. If desired, brush each slice with olive oil and season with salt and pepper before toasting.
- Place 4 oven-safe lion head soup bowls or ramekins on a baking sheet. Ladle the soup into the bowls. Top each bowl with a baguette crouton and a handful of shredded cheese.
- Broil in the oven until the cheese is melted, bubbly, and beginning to brown, about 3 minutes.
Notes
Storage: Store leftover soup in an airtight container in the refrigerator for up to 5 days.
Substitutions:
- Onions: You can also use white or red onions.
- Broth: French onion soup is traditionally made with beef broth, however I like to use mushroom broth to keep this soup vegetarian-friendly. Feel free to use whichever broth you prefer best: beef, chicken, mushroom, or vegetable.
- Bread: You can also use cubed or sliced crusty day-old bread.
- Cheese: You could also use Comté, Swiss, provolone, or fontina cheese in place of gruyère.