Preheat your oven to 400°F and prepare a large sheet of heavy-duty aluminum foil or parchment paper.
Trim the woody ends off the asparagus and place the spears in the center of the foil sheet.
Season the asparagus with half of the sea salt and black pepper, then drizzle with half of the extra virgin olive oil.
Pat the salmon fillet dry with a paper towel and place it directly on top of the bed of asparagus.
Mince the garlic clove finely and press it into the top of the salmon fillet.
Drizzle the remaining olive oil over the salmon and season with the rest of the salt and pepper.
Slice the half lemon into thin rounds and layer them over the salmon, then sprinkle with the fresh chopped dill.
Bring the long edges of the foil together and fold them down tightly, then fold the sides to create a completely sealed pouch that traps the steam.
Place the foil packet on a rimmed baking sheet and bake for 15 to 20 minutes, depending on the thickness of the fillet.
Remove from the oven and let rest for 2 minutes before carefully unfolding the foil to reveal the aromatic, tender fish.