Thirty minutes before you wish to make this tart, remove one of the pastry sheets from your freezer to thaw on the counter. When you're ready to make the tart, preheat your oven to 400 degrees Fahrenheit.
Un-ravel the puff pastry sheet, so you're left with a flat rectangle. Dust your counter top or cutting board with flour, put the pastry sheet on top of that, and dust the top of the pastry sheet with more flour. Roll out the pastry sheet, so you have a nice smooth sheet to work with. You don't have to roll it out too much.
Place the rolled out puff pastry sheet on a parchment or silpat-lined baking sheet, and using the olive oil, brush the edges of the puff pastry, about 1 inch in, creating a 1 inch border around the puff pastry.
Spoon the salsa onto the puff pastry, and evenly spread out to the edge of the olive oil, leaving the 1 inch border on the puff pastry.
Distribute the hatch chiles evenly and top with the sliced tomatoes. Season with salt and pepper.
Bake the tart at 400 degrees Fahrenheit, or until the edges are puffed up and golden brown.
Remove from oven and let cool for 2 minutes. Using the parchment paper, slide the tart onto a cutting surface, and cut into 12 squares with a pizza cutter or large knife. Serve, and enjoy!