Onion soup in a pot

Ingredients:

• 1.5 kg red onion, thinly sliced ​​on a mandoline
• 3 tablespoons unsalted butter
• 2 tsp chopped fresh thyme
• 1 clove garlic, minced
• 1 cup dry white wine
• 6 cups chicken broth, homemade or canned (lightly salted)
• 1 teaspoon coarse salt + more to taste
• 2 tbsp. cognac or brandy (optional)
• 6 slices baguette, 1 cm thick, toasted
• 340 g Gruyere, grated (about 3 cups)

Preparation:

1. In a large soup pot or Dutch oven, melt the butter over medium heat. Add the onion, stir, cover, and cook for 30 minutes, stirring occasionally. Remove the lid, increase the heat to medium-high, and cook until the onion is darkened and caramelized, about 30 minutes. Stir the onion especially frequently toward the end of this stage to prevent burning. Add the thyme and garlic and cook for another 2-3 minutes.
2. Pour in the wine and scrape up any browned bits from the bottom of the pan with a wooden spoon; cook until the wine has reduced by about half. Add the stock and salt, and bring to a gentle simmer. Cover and cook for 30 minutes.
3. Add cognac, if using, and season with salt and pepper to taste. The soup can be prepared up to this point the day before serving and refrigerated. When ready to serve, preheat the oven to broil.
4. Reheat the soup and ladle it evenly into 6 ovenproof bowls. Top each serving with a slice of baguette and about 1/2 cup of cheese. Place the bowls on a baking sheet and broil until the cheese is golden brown. Carefully transfer each bowl to a plate. Serve immediately.