Preheat your oven to 400°F (200°C). Cut four 12-inch squares of parchment paper. If you don't have parchment, aluminum foil can be used, though parchment is preferred for its non-stick qualities.

Place one salmon fillet slightly off-center on each parchment square. Arrange asparagus spears and cherry tomato halves around and on top of the salmon.

Drizzle each fillet and vegetable assortment with about 1/2 tablespoon of olive oil. Season evenly with salt and black pepper. Place a few lemon slices and a sprinkle of chopped dill or parsley on top of each salmon fillet.

To seal the pouch, bring the two longer edges of the parchment paper together over the salmon. Fold the edges over twice, creating a tight seam. Then, fold and crimp the short ends securely to form a sealed, half-moon-shaped packet.

Carefully transfer the sealed parchment pouches to a baking sheet. Bake for 15-20 minutes, or until the salmon is cooked through and flakes easily with a fork. Cooking time may vary based on the thickness of your salmon fillets.

Remove from the oven and serve immediately. To open, carefully cut or tear open the top of each pouch (watch out for steam!). Serve the salmon and vegetables directly from the parchment, or gently transfer to plates.