Preheat oven to 400°.
Combine sugar and water in a small saucepan. Bring to a boil; cook 1 minute or until sugar dissolves. Cool completely. Place sugar mixture and mint in a blender; process until smooth. Combine mint mixture and sliced peaches in a bowl.
Cut 4 (2-inch) circles in puff pastry using a sharp round cookie cutter. Roll each circle of dough into a 4-inch circle on a floured surface. Place on a baking sheet. Bake at 400° for 12 minutes or until golden brown. Top with peach mixture.