- Preheat oven to 200°C.
- Line a large baking tray with greaseproof paper and lay the two puff pastry sheets separated on tray.
- Mix horseradish cream, parmesan and chives together and spread evenly over the two puff pastry sheets.
- Mix potatoes, onion, thyme, garlic powder and salt, and olive oil in a bowl. Evenly divide and arrange between the two pastry sheets.
- Bake in a hot oven for 20 minutes until pastry is crispy and potatoes are tender.
- Top with fresh rocket to serve and cut into 8 pieces.