Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Mince the garlic clove and finely chop the fresh dill leaves.
Trim the woody ends off the asparagus spears and place them on one side of the baking sheet.
Place the salmon fillet on the other side of the baking sheet.
Drizzle the olive oil over both the salmon and the asparagus, then sprinkle with sea salt, black pepper, and minced garlic.
Rub the seasonings into the salmon and toss the asparagus to coat evenly.
Slice the half lemon into thin rounds and layer them over the top of the salmon fillet, then sprinkle the fresh dill over the fish.
Bake for 12 to 15 minutes, or until the salmon flakes easily with a fork and the asparagus is tender-crisp.
Serve immediately, squeezing any remaining juice from the lemon slices over the entire plate.