Forest mushroom soup

Ingredients:

• 3 tablespoons unsalted butter
• 1 small onion, thinly sliced
• 350 g of mixed mushrooms (e.g., brown button mushrooms, shiitake mushrooms, and oyster mushrooms), stems removed, caps finely chopped
• 4 cups chicken broth
• 1.5 tsp Marsala, optional
• About 1/4 cup crème fraîche, for serving
• 1 tbsp chopped green onions
• Olive oil to drizzle

Preparation:

1. Melt the butter in a small saucepan over medium heat. Add the onion and cook, stirring occasionally, until softened, about 12 minutes. Increase the heat to medium-high, add the mushrooms, 1/4 teaspoon of salt, and a few grinds of black pepper. Cook, stirring frequently, until the mushrooms release their liquid but are not browned, about 8 minutes.
2. Add chicken broth and bring to a boil. Simmer over low heat, partially covered, for 30 minutes.
3. Place the mushrooms in a blender and blend until smooth (use caution when blending hot liquids). Add the Marsala, if using, and season with salt and pepper to taste.
4. Ladle the soup into 4 bowls. Top with crème fraîche and sprinkle with green onions. Drizzle with a little olive oil.