1: 1. Mix mayo and mustard for a tangy kick.

2: 2. Add chopped celery for extra crunch.

3: 3. Spice it up with paprika or cayenne pepper.

4: 4. Swap mayo for Greek yogurt for a healthier option.

5: 5. Use avocado instead of mayo for a creamy twist.

6: 6. Add crispy bacon for a savory touch.

7: 7. Mix in fresh herbs like dill or parsley for a burst of flavor.

8: 8. Experiment with different breads like croissants or wraps.

9: 9. Elevate your sandwich with a fried egg on top.