Preheat the oven to 400˚F. Line two baking trays with silicone or parchment paper.
Roll out the puff pastry into a rectangle about 13 x 10 inches. Landscape orient the pastry so you have the 13-inch edge running left to right and the 10-inch edge is vertical. Spread the tapenade all over the pastry. Sprinkle the parmesan on top. Using a pizza wheel cutter or sharp knife, cut the pastry vertically into strips about a 1/2-inch wide. You should end up with about 26 strips.
Pick up the first strip of pastry and place it on your prepared baking tray, twisting it a few times before you put it down. Repeat with the other pastry strips. Brush the egg yolk on the parts of the pastry strips that do not have tapenade on them. This will help give your breadsticks a nice color. Bake in the oven for 6-8 minutes or until the puff pastry is golden brown and cooked through.
These are beautiful laid out on a board or standing up in a glass.