Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Trim the woody, fibrous ends off the asparagus spears and spread them out on one side of the prepared baking sheet.
Place the salmon fillet on the other side of the baking sheet.
Finely mince the garlic clove and chop the fresh dill.
Drizzle the olive oil evenly over both the salmon and the asparagus.
Season everything with sea salt, black pepper, minced garlic, and the fresh dill, rubbing the seasonings into the salmon.
Thinly slice half of the lemon and layer the rounds directly on top of the salmon fillet.
Bake for 12 to 15 minutes, or until the salmon is opaque and flakes easily with a fork and the asparagus is bright green and tender.
Squeeze any remaining juice from the lemon ends over the dish before serving warm.