Tear off a piece of parchment paper large enough for the trout to be enclosed loosely. Place a fillet on the parchment paper. Spread the paste evenly on top of the fillet. Sprinkle with 1 tablespoon of parsley. Fold the parchment to enclose the trout loosely.
Tuck ends underneath, creating a sealed pocket.
Repeat with remaining fillets. Place on a baking sheet and bake 10 to 12 minutes or until the center of the fish is opaque. Serve in the parchment pocket.