Preheat the oven to 400℉. Line a large baking sheet with parchment paper or a silpat mat.
Use a knife or pizza cutter to cut 1 inch squares from the Puff Pastry. You should be able to get 36 squares from one sheet. Place the squares on the baking sheet, leaving about 1-inch space between each square.
Place a small dab of beans on each pastry square. Top with a tomato and an olive. Bake for 15 minutes. Remove baking sheet from the oven and top each with a sprinkle of the shredded cheese. Return the baking sheet to the oven for 3 to 5 minutes, just until cheese is melted and pastry is lightly browned.
For serving, top each with avocado and/or jalapeño and a small dollop of sour cream.
Notes
Make- ahead tip: Prepare nachos through topping with beans, tomato and olive. Wrap the baking sheet with plastic wrap and refrigerate up to 3 hours before baking. To bake, remove from the refrigerator, discard plastic wrap, and bake & finish as directed.