Preheat the oven to 425℉. You'll need 4 parchment baking bags for this recipe (I bought mine at Whole Foods), or you can make your own packets using 4 pieces of parchment (12 inches square), and you can even use foil in its place.
Make the herb butter: Combine butter and fresh herbs in a small bowl.
Place a piece of fish in the center of the paper (or do as I did and bake two larger pieces to be divided upon serving). Add a spoonful of butter in the center of each piece of fish. Sprinkle each piece of fish with salt and pepper. Fold the square in half to enclose the filling, then fold in the edges to seal and form a packet.
Bake for 13 to 15 minutes, until the fish is just opaque and flakes apart easily all the way through. You'll need to open one to check. Serve in the packets (if you wish) and let each person open up the packets, or slide onto a plate with its juices to serve without the parchment. Garnish with lemon wedges, if desired.