Vegetarian Mushroom & Onion Gratinée

Caramelize Onions & Mushrooms

1. In a large heavy-bottomed pot or Dutch oven, melt butter with olive oil over medium-low heat. Add the sliced yellow onions and cook, stirring occasionally, for 30-40 minutes until deeply golden brown and caramelized. Be patient; this is key for flavor.
2. Add the sliced cremini mushrooms to the pot with the caramelized onions. Increase heat to medium and cook for another 10-15 minutes, stirring occasionally, until the mushrooms have released their moisture and are browned.

Build the Soup

1. Sprinkle flour over the onion and mushroom mixture and stir for 1 minute to coat. Deglaze the pot with dry white wine, scraping any browned bits from the bottom. Let it simmer for 2-3 minutes until the liquid has mostly evaporated.
2. Pour in the vegetable broth, add the fresh thyme and bay leaf. Bring to a simmer, then reduce heat to low, cover, and cook for 15-20 minutes, allowing the flavors to meld. Season with salt and black pepper to taste. Remove the bay leaf before serving.

Gratinée

1. Preheat your oven to broil. Ladle the hot soup into oven-safe bowls. Place a slice of toasted crusty bread on top of each bowl of soup.
2. Generously sprinkle the fontina cheese over the bread. Place the bowls on a baking sheet and broil for 2-4 minutes, or until the cheese is melted, bubbly, and golden brown. Watch carefully to prevent burning.
3. Carefully remove from oven. Garnish with fresh chives, if desired, and serve immediately.