Squash and blue cheese may seem like an unusual combination, but this delicious soup never fails to please. For best results, use French Roquefort, which is less brash and salty than some domestic blue cheeses. This soup can also be made with zucchini.
Heat the butter in a large pan over medium heat. When hot, add the leeks and thyme. Sauté, stirring frequently, for 5 minutes or until leeks soften. Add the squash and the stock. Turn the heat to medium-high and cook, covered, for 20 minutes, or until the squash is tender. Remove from the heat and let cool for 15 minutes.
Purée the soup until smooth in a blender or food processor. Return mixture to the pan and add the half and half. Reheat over medium heat until soup is warm; add the cheese and stir until melted. Season to taste with salt and pepper, pour into bowls, and garnish with thyme, if desired. Serve hot.