Preheat your grill or a heavy grill pan over medium-high heat.
In a small mixing bowl, whisk together the olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Trim the woody ends off the asparagus spears and place them in a shallow dish alongside the salmon fillet.
Brush the lemon-herb mixture generously over both the salmon and the asparagus, ensuring they are evenly coated.
Place the salmon on the grill, skin-side down, and cook for approximately 4 to 5 minutes.
Add the asparagus to the grill next to the salmon and cook for 3 to 4 minutes, turning the spears occasionally until they are tender and show light char marks.
Carefully flip the salmon and grill for an additional 2 to 3 minutes until the fish is opaque and flakes easily with a fork.
Remove the salmon and asparagus from the heat and serve immediately with an optional garnish of fresh lemon slices.