I can get between 4 and 6 usable spears off of each endive. This is probably the most expensive item. I typically use the rest of the endives in a salad later, chopping or slicing them and incorporating them with other greens.
The dressed apple mixture can be refrigerated overnight before adding walnuts and blue cheese if desired.
Keep the blue cheese cold just before stirring into apple mixture to keep the blue cheese from turning creamy.