Instructions:
1. Caramelize the Onions:
In a large Dutch oven or heavy-bottomed pot, melt the butter and olive oil over medium heat.
Add the sliced onions and cook, stirring occasionally. After about 10 minutes, sprinkle the onions with a pinch of salt and the teaspoon of sugar. This helps the onions release their moisture and caramelize more evenly.
Continue cooking the onions, stirring frequently, for 30-40 minutes, until they are golden brown and deeply caramelized. Be patient—this step is crucial for developing the soup’s rich flavor!
2. Add Garlic and Deglaze:
Add the minced garlic and cook for another 1-2 minutes, until fragrant.
If using wine, pour in the dry white wine to deglaze the pot. Scrape up any browned bits from the bottom of the pot, which will add depth to the flavor. Let the wine reduce for about 3-4 minutes.
3. Make the Broth:
Add the beef broth to the pot, along with the thyme sprigs and bay leaves. Bring the soup to a simmer and cook uncovered for about 20-30 minutes, allowing the flavors to meld together.
Season the soup with salt and pepper to taste. If you’d like a thicker consistency, you can whisk in 1 tablespoon of flour at this point, stirring it well and simmering for another 5-10 minutes to thicken.
4. Toast the Bread:
While the soup is simmering, preheat your oven to 400°F (200°C).
Place the baguette slices on a baking sheet and toast them in the oven for about 5-7 minutes, or until they are golden and crispy. You can also rub the toasted bread with a garlic clove for extra flavor, if you like.
