HEAT butter in a 4-quart saucepot. Saute carrot, onion and celery until tender. Remove from heat and blend in flour. ADD curry powder, salt, chicken broth, Worcestershire sauce, peanut butter and evaporated milk. Puree mixture in batches using a blender or food processor. RETURN soup to pot; bring to boil. Simmer until thickened. Stir in fresh parsley. Season to taste with salt and pepper. Garnish with additional parsley.