1.Preheat oven to 220°C (200°C fan-forced). Oil and line oven trays with baking paper.
2.Combine cheddar cheese and parmesan cheese in small bowl.
3.Place spinach in fine sieve; squeeze excess water from spinach. Spread half the spinach over one sheet of puff pastry; sprinkle with half the cheese mixture. Top with another sheet of puff pastry; spread with remaining spinach, sprinkle with remaining cheese.
4.Cut pastry stack in half; place one stack on top of the other, press down firmly. Cut pastry crossways into 24 strips; twist strips, pinching ends to seal.
5.Place strips on trays; bake about 15 minutes or until browned and crisp