On a work surface, place an 18-inch-long piece of foil, preferably non-stick, with the long side parallel to the countertop.
Arrange half the potatoes on the oiled side of the foil and sprinkle with a pinch of salt and a pinch of pepper.
Place half the snap peas over the potatoes, followed by half the cherry tomatoes. Sprinkle lightly with salt and pepper, and drizzle with 2 teaspoon oil. Place a salmon fillet over the vegetables and spread with flavorings.
Fold and seal the packet:
Fold the foil over the fish so the ends meet. Fold all three open sides to make a border of about 1 inch and crimp them to tightly seal the packet. Place on a baking sheet.
Repeat with the second sheet of foil, vegetables, and salmon.
Bake the packets:
Bake the packets for 20 to 22 minutes, or until the salmon and vegetables are cooked through.
Carefully open one of the packets to peek. The internal temperature of the thickest part of fish should register 140°F on an instant-read thermometer. (Note that the fish will continue to cook for a few minutes once it is removed from the oven.)
Serve the salmon:
Open the packets carefully (be prepared for hot steam to escape.) Slide a large spatula under the potatoes and transfer the vegetables and fish to dinner plates. Garnish with a few sprinkles of chopped parsley and green onions.