Stilton and Watercress Soup

2 tablespoons unsalted butter
2 medium leeks, white part only, trimmed of roots and tough outer leaves, thinly sliced crosswise, and swirled vigorously in a bowl of cold water to remove any grit
Kosher salt and freshly ground black pepper
2 baking potatoes, peeled, cut into quarters, and placed in a bowl with water to cover
4 cups Chicken Stock or high-quality canned low-sodium chicken broth
2 bunches watercress, tough stems removed, washed and coarsely chopped
1 cup heavy cream
3 ounces Stilton (If Stilton is unavailable, substitute French Fourme d’Ambert or Italian Gorgonzola naturale, also called “aged” Gorgonzola—not dolce, or “sweet, “ Gorgonzola)

Garnishes (optional):

12 very thin slices peeled and cored apple (keep covered with lightly salted water)
4 to 6 small sprigs watercress, large stems removed
2 to 3 teaspoons chopped walnuts

This recipe produces a lighter soup with a smooth, creamy body infused with the spectacular flavor of Stilton cheese.

Melt the butter in a large heavy saucepan over medium heat. Add the leeks, season with salt and pepper, and cook until tender, about 8 minutes.
Remove the potatoes from the water and add them to the saucepan. Add the chicken stock, season with salt, and bring to a boil. Lower the heat and simmer until the potatoes are fork-tender, about 20 minutes. Add the watercress and simmer until it’s tender but still green, 3 to 4 minutes.
Carefully purée the soup in a food processor. Pour the purée through a coarse strainer into a clean pan. Heat the soup over medium heat until hot. Add the cream and Stilton, stirring constantly until the cheese has melted. Taste and adjust the seasonings.
Ladle the soup into warm bowls. If using the garnishes, float a few slices of apple and a sprig of watercress atop each portion. Sprinkle with the chopped walnuts, and serve immediately.