Wash the watermelon radish well to remove any dirt or impurities. Using a mandolin slicer or knife, slice the watermelon radish thin. Stack the radish in a clean glass jar and add the peppercorns and bay leaf. Set aside.

Using a small saucepan, combine the water, vinegar, salt, and coconut sugar. Place over medium heat and whisk to combine. Allow to come to a simmer for 3-4 minutes, until the sugar is dissolved. Remove from the heat.

Carefully pour the liquid over the watermelon radish, fully covering the radish. Allow to cool before covering the jar with a lid and placing it in the fridge. Allow to cool in the fridge for 45 minutes to an hour before enjoying and keep for up to a week.