Serve the salad immediately after dressing so that the lettuce and nuts are crisp and crunchy, not soggy. If you'd like to prep ahead, you can make the salad dressing at least a week in advance. Store leftover dressing in an airtight container in the refrigerator for 1-2 weeks. You can also make the candied pecans in advance and store them in an airtight jar in your pantry for about a month.