Preheat your grill or grill pan over medium-high heat.
In a small bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, chopped parsley, and dill to create the marinade.
Season the salmon fillet evenly with sea salt and black pepper, then brush half of the lemon-herb mixture over the flesh side.
Place the salmon on the grill, skin-side down, and cook for about 4-5 minutes without moving it to ensure a crispy skin.
While the salmon cooks, lightly mist the asparagus spears with a touch of oil and a pinch of salt.
Carefully flip the salmon and grill for another 3-4 minutes until the internal temperature reaches 145°F and the meat flakes easily with a fork.
Add the asparagus to the grill alongside the salmon for the final 4-5 minutes of cooking, turning occasionally until tender and charred.
Remove the salmon and asparagus from the grill and drizzle the remaining lemon-herb mixture over the fish before serving immediately.