Until you’ve tried the ‘set it and forget it’ style of cooking with an instant pot or a slow cooker, preparing dinner can seem like an incredibly daunting task. But this simple French onion soup recipe takes all of the stress out of cooking. The dish does, admittedly, take a significant amount of time to cook, but you’re only spending a few minutes putting everything together!
Try serving this warm, cozy soup as an appetizer when friends come over for dinner, or pair it with a colorful salad and enjoy it as an entree! (Suggested substitutions are included for gluten-free, dairy-free and vegan options.)
Slow Cooker French Onion Soup
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Prep Time: 3 minutes
Cook Time: 17-20 hours
- 3 lbs yellow onions, julienned
- 2 tbsp unsalted organic, grass-fed butter, melted
- 2 tbsp extra virgin olive oil
- 2 ½ teaspoons kosher salt
- freshly ground black pepper to taste
- 2 sprigs fresh thyme
- ¼ cup balsamic vinegar
- 8 cups beef broth or vegan broth
- optional: ⅓ cup brandy
- 4 to 6 whole grain or gluten-free baguette slices, toasted (1 slice per bowl)
- 1 ⅓ to 2 cups grated Gruyere cheese or nutritional yeast (⅓ cup per bowl)
- Add onions, butter, olive oil, salt, and black pepper to a large slow cooker.
- Set the slow cooker to low and cook overnight or for 10-12 hours.
- Add the broth, balsamic vinegar, and fresh thyme. Cover and continue cooking on low for an additional 6 to 8 hours.
- Season to taste with additional salt and pepper. (Optional: add brandy)
- Preheat the oven to 350 degrees Fahrenheit (180 degrees Celcius).
- Spoon the soup into oven-safe bowls. Place the bowls on a baking sheet and top with a baguette slice and the cheese or nutritional yeast.
- Bake for 20 to 30 minutes, or until the cheese is completely melted.
- Broil for 2 to 3 minutes to brown the cheese. Remove from the oven and let cool for 5 minutes before serving.
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