French onion soup with porcini mushrooms

Ingredients:

• 110 g butter
• 4 large onions, sliced ​​into very thin rings
• 1 teaspoon ground thyme
• 30 g dried porcini mushrooms
• 1/4 - 1/3 tbsp. dry sherry
• 1 cup white wine
• 1 small bunch of parsley sprigs, sage and fresh bay leaf
• 2 liters of beef broth
• 8 slices of baguette, 1 cm thick.
• 1 large clove of garlic, peeled and halved
• 1.5 cups grated Gruyere
• 0.5 tbsp. grated parmesan

Preparation:

1. Heat a large Dutch oven over medium heat. Add 6 tablespoons of butter and melt. Add the onion and thyme, season with salt and pepper to taste. Cook, stirring occasionally, until the onion is caramelized, about 40-45 minutes.
2. Meanwhile, place the mushrooms in a small saucepan and cover with a couple of cups of water. Bring to a boil over high heat, then reduce the heat to low and simmer until the mushrooms plump up.
3. Add sherry to the pot with the onions to deglaze, then stir in the wine. Remove the mushrooms from the broth with a slotted spoon and place them on a cutting board. Chop them and add them to the onions. Add almost all of the mushroom broth to the soup, reserving about 1/2 cup (about 1 cup) separately. Add the herb bundle and beef broth to the pot and simmer for 30-45 minutes. Cool and refrigerate if making ahead. Reheat the soup over medium heat, covered, and toast the croutons when ready to serve.
4. Preheat the oven to 220°C (425°F). Toast the bread on a rack over a baking sheet until richly golden. Brush the bread with butter and generously rub the slices with chopped garlic. Sprinkle the croutons with cheese and return them to the oven until the cheese melts and begins to bubble. For a more impressive presentation, arrange the croutons on top of bowls of soup, place them on a baking sheet, then sprinkle with cheese and bake in the oven.
5. Ladle the soup into bowls and serve with cheese croutons.