- 4 tbsp. butter
- 3 large white onions, thinly sliced into half moons
- 2 tbsp. all-purpose flour
- Kosher salt
- Freshly ground black pepper
- 1/2 cup white wine
- 2 cups low-sodium chicken stock
- 4 cups low-sodium beef stock
- 8 sprigs fresh thyme, plus more for garnish
- 8 baguette slices
- 1 cup grated cheese
In a large pot over medium-high heat melt butter. Add onions and cook, stirring occasionally, until deeply golden about 25 minutes. Add flour and cook 1 minute until no longer raw. Season with salt and pepper, and then add white wine and let simmer for about 3 minutes. Add chickened beef stocks and thyme and bring to a boil. Reduce heat to medium and simmer 15 minutes. Season with salt and pepper and remove thyme.
Preheat broiler to high. Place two baguette slices on a large baking sheet and top each slice with 2 tablespoons of cheese. Place under broiler until cheese is bubbling and golden brown, about 1 minute.
Serve soup in bowls or large mustard with baguette slice on top. Garnish with a thyme sprig.
Serves 4 people. Prep time 20 minutes. Total time 1 hour 5 minutes.