Heat the oven to 375°F. Pat dry the salmon fillets and sprinkle them with pepper.
To prepare each fillet, center it on a short end of a sheet of parchment, a few inches from the edge. Top it with 1 tablespoon of the pesto, then squash, olives, shallot, and capers. Fold the parchment in half crosswise over the salmon. Fold in a corner of the creased edge to seal it. Working around the perimeter of the packet, make another overlapping fold, then continue in this manner, overlapping as you go, until the packet is completely sealed.
On a large baking sheet, place the pouches and bake until the salmon can be easily flaked with a fork, about 20 minutes.
Serve with additional pesto and a drizzle of olive oil. Serve over pasta.
