Put the potatoes into a 4 quart pot and cover with water. Bring the potatoes to a boil, and continue cooking until the potatoes are just cooked through, about 25 minutes. Drain and let cool completely. Remove the peel and cut into 1/4-inch slices. You can cook the potatoes the day ahead.
Cut 6 – 12 x 24 inch pieces of heavy duty aluminum foil. We prefer the easy release non-stick version for this dish. Fold each piece in half to make a 12 x 12 inch square. With the dull side up, place 3 to 4 slices of potatoes in a row down the middle of the square. (If you're using the optional banana leaf, you would place it down on the foil before adding the potato slices.) Spoon 1 tablespoon of the Garlic Mojo over the potatoes, then sprinkle with salt and pepper. Place the salmon fillet on top, and drizzle on another tablespoon of Garlic Mojo. Sprinkle salt and pepper over the fish, then place several sprigs or leaves of whatever fresh herb you'd like on top. Repeat these steps with the remaining pieces of salmon.
Seal the package by bringing the top and bottom of the foil up to the center and folding the two sides together. Fold the top over a second time to ensure a good seal. Double fold both ends to create an airtight package.
Slide the packages onto a medium-high grill and cook for about 8 to 10 minutes. Remove from the grill and place on individual plates, along with several wedges of lime. Let each guest open their own package and add a squeeze of fresh lime over their fish.
Pick potatoes that are similar in size so that they cook evenly.