Pre-heat the oven to 180°C/350°F/Gas Mark 4 and place parchment paper on a baking tray.
Cut the pastry into 4 and roll each portion to a square about 3-4mm thick. Place them on the tray and prick with a fork. Bake for 10-15 minutes until slightly golden and risen. Remove from the oven and set to one side.
Heat the Original Whirl in a frying pan and add the onions, balsamic vinegar and water - sauté for about 10 minutes until starting to caramelise.
Add the beetroot and thyme, cook for a further 5 minutes until the onions are soft and the liquid has all dissolved.
Spoon onto the prepared tarts and top with crumbled goats cheese.
Return to the oven and bake for a further 10 minutes until the pastry is golden and the cheese has started to brown.
Remove from the oven and sprinkle with the toasted walnuts.
Tip ‘For best results! Both the pastry tart bases and the caramelised filling can be prepared in advance and put together when required for the final bake.