In a large saucepan, melt the butter over medium-high heat. Add the onions and cook, stirring, until just beginning caramelize, about 10 minutes. Add the garlic and cook, stirring, for 30 seconds. Add the potatoes, salt, pepper, cayenne, and bay leaf, and cook, stirring, for 3 minutes. Add the stock and bring to a boil. Reduce the heat to medium-low and simmer until the potatoes are tender, 25 to 30 minutes.
Remove and discard the bay leaf. Remove from the heat and puree with a hand-held immersion blender, or in batches in a food processor, until smooth. Add the light and heavy creams, and stir well to blend. Gently reheat and barely simmer, being careful not to boil. Add 3/4 cup of the cheese, the thyme, and Port, and whisk until the cheese is just melted. Adjust the seasonings to taste.
Ladle the soup into bowls, and top each with some of the remaining 1/4 cup of cheese and the crumbled bacon. Serve immediately with the Blue Cheese and Walnut Crumpets.
Makes 8 servings
BLUE CHEESE AND WALNUT CRUMPETS:
In a bowl, cream together the cheese and butter. Add the Port, walnuts, and salt, and mix until creamy.
Lightly toast each crumpet or muffin half on a rack. Spread about 1 heaping tablespoon of the cheese mixture onto each of the crumpets or muffin halves and top each with 1 walnut half. Toast until just bubbling. Serve immediately.
Makes 16 servings