In a small glass bowl, whisk together the lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Lightly brush the salmon fillet and the trimmed asparagus spears with the extra virgin olive oil.
Evenly coat the flesh side of the salmon fillet with the prepared lemon-herb mixture, pressing it gently into the fish.
Preheat your grill or a cast-iron grill pan over medium-high heat until it is hot and lightly smoking.
Place the salmon on the grill, skin-side down, and cook undisturbed for 4-5 minutes until the skin is crispy and releases easily from the grates.
Arrange the asparagus spears on the grill next to the salmon, turning them occasionally with tongs to achieve even charring.
Carefully flip the salmon and cook for an additional 3 minutes, or until the internal temperature reaches 145°F and the asparagus is tender-crisp.
Transfer the salmon and asparagus to a plate and let the fish rest for 2 minutes before serving to ensure maximum juiciness.