Preheat oven to 400F/200°C To a 12-inch long sheet of foil (I use Reynold's Heavy Duty Non-Stick), add half the potato slices in a pile in the center of foil. Slightly fan out the potatoes so air can circulate. Make sure potatoes are sliced very thin so they cook through in the same amount of time it takes the salmon to cook.
Evenly drizzle the potatoes with about 1 tablespoon of olive oil, season with salt and pepper, and repeat process with another sheet of foil and the remaining potato slices.
Top each pile of potatoes with 1 salmon filet.
Evenly drizzle each salmon filet with about 1 tablespoon olive oil.
Squeeze half the juice of the orange over one salmon filet and half the juice over the other filet.
Squeeze half the juice of the lemon over one salmon filet and half the juice over the other filet.
Season each salmon filet with salt and pepper.
Seal foil packets, making sure to tightly crimp the seams so the olive oil and citrus juices don't leak. Place packets on baking sheet and bake for about 25 to 30 minutes. Carefully open one packet to check for doneness of both salmon and potatoes and if necessary, return to the oven for an additional 5 minutes, or until done.