In a measuring cup, measure out the coconut milk. Add enough regular milk to make 2 cups.
In a medium saucepan, whisk together the mix and the milk mixture. Heat over medium heat, whisking constantly, until thick and bubbly. Remove from heat and whisk in the vanilla bean paste.
Allow pudding to cool slightly, then cover and refrigerate until chilled, several hours or overnight.
Make the canapés:
Allow puff pastry to thaw at room temperature for 20-30 minutes, until workable but still cold. It is important that puff pastry remain cold when working - if it gets too warm/soft while working, stick it back in the fridge or freezer for a few minutes to firm back up, then continue working.
Preheat oven to 400 degrees. Line a sheet pan with parchment paper; set aside.
On a lightly floured surface, unfold the puff pastry and roll out slightly, just to reseal the creases. Using a 1 1/2 to 2-inch cookie cutter, cut out rounds of puff pastry, cutting straight down then twisting to remove. Place the rounds on the prepared baking sheet. You will probably be able to get about 20 rounds, depending on the size of your cookie cutter and your puff pastry.
With a slightly smaller cookie cutter, score the puff pastry. Using a fork, poke holes (or dock) the centers of the circles. This will allow the edges to rise but the centers to not rise as fully, giving you a little tart-like shell.
Bake the rounds for about 15 minutes, or until golden brown and puffed (times may vary depending on your puff pastry, so check your package directions to be sure).
Allow shells to cool completely before filling.
Assemble the canapés:
Place the prepared pudding in a piping bag, or in a zip-top bag with the corner cut out. Pipe the pudding into the center well of each shell. Garnish with sliced fruit.