Preheat your outdoor grill or a cast-iron grill pan over medium-high heat until it is lightly smoking.
Pat the salmon fillet completely dry with a paper towel to ensure a clean sear and prevent sticking.
In a small glass bowl, whisk together the extra virgin olive oil, lemon zest, lemon juice, garlic powder, sea salt, and black pepper.
Brush the herb marinade generously over the salmon fillet and toss the asparagus spears in the remaining mixture until coated.
Place the salmon on the hot grill, skin-side down first, and cook undisturbed for 4-5 minutes to develop a golden crust.
Arrange the asparagus spears on the grill next to the salmon, turning occasionally to achieve even charring.
Carefully flip the salmon using a wide spatula and grill for another 3-4 minutes until the center is just opaque and flaky.
Transfer to a plate, garnish with fresh chopped parsley, and serve immediately for peak freshness.