Pastry chef Arnaud Delmontel rolls out dough for croissants and pain au chocolat that later emerge golden and fragrant from the oven in his Paris patisserie. In recent months he has had to pay increasingly more for the butter so essential to their flavor — a price he says has shot up 25% since September alone. But he is refusing to follow some of his competitors who have started making their croissants with margarine. (AP video for Alexander Turnbull)