Prepare the dressing by combining mayonnaise, apple cider vinegar, mustard, honey, salt, crushed red pepper flakes, and pepper in a bowl. Whisk until well-combined. Combine chickpeas, celery, apple, strawberries, parsley, and walnuts in a large bowl. Stir in the dressing and toss until evenly coated. Refrigerate for about 30 minutes before serving, or up to 5 days. Serve on a bed of salad greens or spinach.