Preheat the oven to 375F/190C.

Start by rolling out the puff pastry a little then putting a small skillet/frying pan on top to measure and cut out a round disk the size of the skillet.

Peel the beetroot if not already peeled and cut into slices around ¼in/ ½cm thick.

Melt the butter in the skillet/frying pan then add the vinegar and sugar. Stir until dissolved and cook a minute.

Lay the beetroot slices around the pan, working from the outside, layering round then filling any gap in the middle. Do this while the butter-sugar mix is still on the heat, being careful not to touch it with your fingers.

Remove the pan from the heat and dot chunks of goats cheese on top of the beetroot.

Carefully lay the pastry disk over the beetroot and tuck the edges down as best you can round the sides.

Bake in the oven until light brown on top, around 20 minutes.

Allow the tart to rest a minute or two before inverting. Serve warm or cold.