Line a large baking tray with greaseproof paper and lay the two puff pastry sheets separated on tray.
Mix horseradish cream, parmesan and McCormick Chives Chopped together and spread evenly over the two puff pastry sheets
Mix potatoes, onion, McCormick Thyme Leaves, Garlic Powder and olive oil in a bowl, seasoning to taste with McCormick Sea Salt. 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.