In a large bowl, toss together the cabbage, radishes, apple, celery, and herbs until well combined.
Meanwhile, whisk together Pompeian Robust Extra Virgin Olive Oil, vinegar, mustard, maple syrup (or honey), and salt. Adjust to taste with additional vinegar and salt. Garnish with reserved celery leaves and apple slices
Dress the slaw with your dressing and either serve immediately, or store in an airtight container for up to 4 days and enjoy!