Place a sheet of parchment paper onto a rimmed baking sheet and set the fillet in the center. Drizzle salmon with olive oil, rub using a spoon over the whole surface, then season with salt, pepper, and the dried dill or Italian seasoning.
To make the sauce, stir together all ingredients in a bowl.
Spread the sauce evenly over the salmon. Sprinkle with remaining herbs.
If your salmon fillet is very large, as mine was, you will need two sheets of parchment paper. Place the second sheet of parchment paper over the salmon. Holding the side edges together, fold them toward the center and tie using string to seal closed so no juices leak. Repeat with the top and bottom edges, forming a packet. If your salmon is smaller, you may be able to create a packet with just one sheet of parchment.
Bake the salmon in its parchment paper pack at 350 degrees F for 22-30 minutes (see note).
When you untie the packet, be careful as steam may escape, with the risk of burns. Top with additional fresh chopped herbs if desired and serve.