Rinse salmon and pat dry.
On the center of each of 6 sheets of cooking parchment (each about 12 by 15 inch, set a piece of salmon.
Place 2 or 3 sprigs of cilantro on each fillet.
Mix soy, vermouth, sesame oil, and ginger; drizzle equal amounts of this mixture on each piece of fish.
Bring 2 opposite sides of parchment together and fold over twice.
Fold ends over 2 or 3 times and tuck underneath fish.
Place enclosed packets on a 12- by 15-inch baking sheet.
Bake in a 450° oven just until fish looks slightly translucent and wet in thickest part (cut a tiny slit through paper to test), 10 to 15 minutes.
Transfer to dinner plates.
Unwrap packets, tucking paper under fish.