Make the dressing: In a mason jar combine the sherry wine vinegar, olive oil, dijon, shallot, salt and pepper. This recipe will make 1 cup of dressing so you'll have some left over. Store any extra dressing in the refrigerator for up to 2 weeks.
Slice the avocado lengthwise and then into thin slices and place on a plate. Use firm avocados for easier slicing.
Using a peeler, remove the skin from the cucumber. Spiralize the cucumber and spread on top of the avocado slices.
Garnish your cucumber avocado salad: Add a few slices of red onion, pour vinaigrette over the salad, garnish with chives, red pepper flakes, salt and pepper. Enjoy!