Place 30g walnuts in a food processor and pulse until finely chopped.
Add 150g cooked beetroot and process until well combined. Season with salt and pepper to taste.
Unroll the 320g sheet of puff pastry, leaving it on its original paper.
Spread the beetroot mixture over the top, then crumble 65g goats cheese into small pieces on top.
Roll the pastry up tightly along the long side to the middle, then repeat from the other side.
Wrap in the paper and chill in the fridge for several hours. If you're short of time 20 minutes in the freezer should do it.
Pre-heat the oven to 180°C (fan)/200°C/gas mark 6. Line two baking trays with greaseproof paper.
Remove the palmier roll from the fridge and remove the paper. Using a sharp knife cut into one cm piece and place on the baking tray.
Bake in the centre of the oven for 15-20 minutes until the pastry is golden brown.