Preheat the oven to 200°C (approximately 400°F). Roll the pastry out thinly on a lightly floured surface. Rinse and peel the pears. Remove the seeds and cut into fine columns. Place the pastry on a lined baking sheet and brush with the pear juice (or maple syrup) with a 1-2 cm margin. Arrange the pear slices on the pastry, overlapping. Bake for 30-40 minutes.
Brush the hot tart with a little pear juice and serve immediately.