- 3 tablespoons butter
- 1 bulb fennel, diced
- 2 leeks, white parts only, trimmed and sliced
- 1 large Spanish onion, diced
- 4 cloves garlic, minced
- 6 cups chicken stock
- 3 large Yukon Gold potatoes, peeled and diced into 3/4-inch pieces
- 2 cups fresh porcini mushrooms
- 1 teaspoon dried thyme
- 2 cups heavy whipping cream
- 1/2 cup cream sherry
- 1/2 teaspoon Worcestershire sauce
- salt and ground black pepper to taste
- Melt butter in a large pot over medium heat. Add fennel, leeks, onion, and garlic; cook and stir until softened, about 10 minutes. Stir in chicken stock, potatoes, porcini mushrooms, and thyme. Bring to a boil; reduce heat to medium-low and simmer until potatoes are tender, 30 to 35 minutes.
- Remove pot from the heat; stir in heavy cream, cream sherry, Worcestershire sauce, salt, and black pepper. Puree soup with an immersion blender until smooth.
- Return pot to the heat. Simmer soup until warmed through, about 10 minutes.