In a medium saucepan, combine the cider vinegar and fresh cranberries. Cook over medium heat until the cranberries have softened. Remove the pan from heat and add olive oil, white sugar, kosher salt, and black pepper. Blend the mixture until smooth, then refrigerate until chilled.
Prepare the pears by coring and julienning one, while coring and dicing the other.
In a large serving bowl, combine the romaine lettuce, Belgian endive, diced pears, toasted walnuts, and Gorgonzola cheese. Drizzle with the cranberry dressing and toss until the salad is evenly coated.
Divide the salad among plates, garnishing each with the julienned pear. Add extra walnuts as a topping, if desired.