Roll the pastry out into a 12x14" rectangle on a well-floured surface. In a food processor, blend tomatoes and rosemary until it becomes a paste. Spread half of the tomato paste evenly over the puff pastry. With the shortest end facing you, roll the edges of the pastry inward towards each other, meeting in the middle. Beat the egg, and brush it down the center of the roll to stick the sides together. Repeat for the other sheet of puff pastry. Place the rolls on a baking sheet and chill for 30 minutes.

Preheat the oven to 400. Remove the rolls from the refrigerator and slice into 1/2" thick pieces. Arrange pieces on the baking sheet, and brush with the beaten egg. Bake for 10-12 minutes or until the pastry is puffed and golden.