In a medium bowl add the mayonnaise, relish, ketchup, salt, and pepper in a bowl and whisk until combined. This is best if left in the fridge overnight and used the next day.
Add to your favorite salad as a dressing or as a great vegetable dip!
Notes
If you enjoy a smoother thousand island dressing you can always use an immersion blender for 10-20 seconds to make it to your favorite texture.