Description
This hearty Mushroom & Caramelized Onion Soup with Cheesy Toasties is a comforting blend of rich caramelized onions, savory mushrooms, and fragrant herbs in a flavorful broth. Topped with crispy toasted baguette slices loaded with melted Gruyère and Parmesan cheeses, this soup makes for a perfect meal during colder months or when you crave something warm and indulgent.
Ingredients
Scale
Soup Base Ingredients
- 4 tbsp unsalted butter
- 4 large yellow onions, thinly sliced
- 2 cloves garlic, finely chopped
- 2 bay leaves
- 2 sprigs fresh thyme
- 1 cup dry white wine
- ¼ cup all-purpose flour
- 8 cups beef broth (or vegetable broth for vegetarian option)
- Salt & pepper to taste
Mushrooms
- 1 tbsp unsalted butter
- 1 tbsp olive oil
- 1 clove garlic, finely chopped
- 24 oz cremini mushrooms, quartered
- 1 tsp fresh thyme
Cheesy Toasties
- 1 baguette, sliced
- 8 oz Gruyère cheese, grated
- ½ cup Parmesan cheese, grated
Instructions
- Caramelize the Onions: Melt 4 tablespoons of unsalted butter in a large pot over medium heat. Add the thinly sliced yellow onions, bay leaves, sprigs of fresh thyme, and a pinch of salt. Cook, stirring occasionally, for 30 to 40 minutes until the onions are deeply caramelized and golden brown.
- Add Garlic and Deglaze: Stir in the finely chopped garlic and cook for about a minute until fragrant. Pour in the dry white wine to deglaze the pot, scraping up any browned bits from the bottom. Simmer until the wine has reduced by half, enhancing the flavor of the soup base.
- Thicken the Soup: Sprinkle the all-purpose flour over the caramelized onions and stir well, cooking for 2 minutes to eliminate the raw flour taste. Gradually whisk in the beef broth (or vegetable broth) until fully combined. Bring the mixture to a simmer and cook for 20 to 25 minutes to allow the flavors to meld.
- Sauté the Mushrooms: While the soup simmers, heat 1 tablespoon butter and 1 tablespoon olive oil in a skillet over medium-high heat. Add the finely chopped garlic and sauté until fragrant, about 30 seconds. Add the quartered cremini mushrooms and fresh thyme, cooking for 10 to 12 minutes, stirring occasionally, until the mushrooms are nicely browned and tender.
- Prepare the Cheesy Toasties: Preheat the broiler. Toast the baguette slices lightly under the broiler. Remove them and top each slice with grated Gruyère and Parmesan cheeses. Return the toasties to the broiler and cook just until the cheese is bubbly and golden, about 2 to 3 minutes. Watch carefully to prevent burning.
- Assemble and Serve: Remove bay leaves and thyme sprigs from the soup. Ladle the hot soup into bowls, dividing the sautéed mushrooms evenly among them. Top each bowl with cheesy toasties, garnish with additional fresh thyme and a sprinkle of Parmesan cheese if desired, and serve immediately for a delicious, comforting meal.
Notes
- You can substitute beef broth with vegetable broth to make this recipe vegetarian-friendly.
- Use dry white wine like Sauvignon Blanc or Pinot Grigio for deglazing to enhance flavor without overwhelming the soup.
- Gruyère cheese adds a nutty flavor, but you can substitute with Swiss or mozzarella if unavailable.
- For gluten-free option, use gluten-free flour and bread alternatives.
- Caramelizing onions is a slow process but essential for depth of flavor; do not rush this step.
