Preheat oven to 375 degrees F.
Rip off 4 pieces of parchment to form packets each about 12-inches long. Season fish with salt and pepper. Place a piece of parchment in a shallow dish then in the center of the paper stack 1/4 of the scallions and shiitakes, layer with slices of ginger and garlic and top with fish. Combine the honey, vinegar and tamari and pour 1/4 of the sauce over fish. Fold over the top of the parchment then roll the sides in to form a sealed pouch. Repeat with remaining parchment and ingredients. Arrange the pouches on a baking sheet and roast in hot oven 12 to 14 minutes.