In a small saucepan, add vinegar, water, maple syrup, salt and peppercorns. Gently simmer for 5 minutes then leave to cool.
Hull the strawberries and chop them in halves or quarters depending on their size. Put them into a clean Mason jar, then pour the cool liquid over the top. Tap the jar on the counter a few times to get rid of air bubbles, then seal tightly with a lid and put in the fridge for 24 hours or up to a week.
Served spooned on top of vanilla ice cream, thick Greek yogurt or chocolate cake.
For a parfait: Spoon alternate layers of strawberries and sweetened whipped cream into a small sundae glass. Top with more strawberries and crushed biscuits.