Preheat the oven to 400 degrees. Remove the puff pastry from the package and place on a lightly floured surface. Dust a little more flour on top to make it easy to cut.
Using a cookie cutter, punch out as many flowers as you can and press them into the wells of a mini muffin tin, lightly flattening the "petals". Use a fork to poke the bottom of the puff pastry.
In a small saucepan, combine the blueberries, sugar and water. Bring to a boil over medium-high heat and allow to bubble for 3-5 minutes until the blueberries begin to pop and the mixture begins to thicken.
Scoop the mixture into a piping bag {fitted with your desired tip} or a zip top bag with the tip snipped from one corner, and pipe into each of the puff pastry blossom shells.