Preheat oven to 425 Fahrenheit.
Lay the pieces of foil on a work surface and place one fillet crosswise in the center of each piece (if space is limited, do one at a time). Sprinkle the fillets on both sides with salt and pepper and place the darker, smoother side of the fillet against the foil (that would be the side the skin was on).
In a medium-size bowl, combine all the remaining ingredients. Divide the mixture evenly over the fillets. Seal the packets, making sure to leave some space inside them, by folding the long ends together first, then by folding the sides together, and by turning the side folds upwards to reduce the risk of leakage.
Put the packets on a baking tray and bake them for 15 minutes. Remove the tray from the oven and LET THE PACKETS SIT 5 MINUTES LONGER to finish cooking.
To serve the fish, carefully open each packet and, with a long spatula, lift the fillets with their topping off the foil, and place them on individual plates. You could also just let each diner open their own packet, which is especially effective if parchment is used.