mushroom & leek soup with thyme cream

I finally made it to the farmer's market last weekend and bought some leeks and mushrooms, among other things. It being one of the few really hot days of the summer I decided to make this earthy soup. Nothing like sweating while you eat. I will definitely be making it again this fall.

Mushroom and Leek Soup with Thyme Cream
via Epicurious

1/2 cup heavy cream
3 teaspoons fresh thyme, chopped
6 tablespoons (3/4 stick) unsalted butter
2 pounds crimini (baby bella) mushrooms, cut into 1/4-inch-thick slices (10 1/2 cups)
3 large leeks, white and pale green parts only, cut into 1/4-inch dice (2 1/2 cups)
6 tablespoons all-purpose flour
6 cups chicken stock or canned low-sodium chicken broth
1 1/2 teaspoons salt
3/4 teaspoon freshly ground black pepper

Using electric mixer, beat cream just until soft peaks form. Fold in 2 teaspoons thyme. Cover and refrigerate at least 2 hours to blend flavors. (Thyme cream can be made up to 1 day ahead. If cream separates, whisk until soft peaks re-form. ) Remove from refrigerator 1 hour before serving to come to room temperature.

In 4-quart stock pot over moderately high heat, heat 2 tablespoons butter until hot but not smoking. Working in 2 batches (add 2 more tablespoons butter before second batch), cook mushrooms, stirring occasionally, until lightly browned, about 8 minutes. Transfer to large bowl.

In same stock pot over moderate heat, heat remaining 2 tablespoons butter. Stir in leeks, cover, and cook, stirring often, until soft, about 5 minutes. Add cooked mushrooms, sprinkle with flour, and stir until flour is evenly distributed. Stir in stock, then salt, pepper, and remaining 1 teaspoon thyme. Bring to boil, stirring often, then reduce heat to low, set lid ajar, and simmer 20 minutes. (Soup can be made up to 2 days ahead and refrigerated, covered. Reheat before serving.)

Divide soup among 8 bowls and top each portion with dollop of thyme cream. Serve immediately.