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