Preheat your grill or grill pan to medium-high heat and lightly oil the grates to prevent sticking.
In a small bowl, whisk together the olive oil, fresh lemon juice, lemon zest, chopped dill, chopped parsley, garlic powder, sea salt, and black pepper.
Pat the salmon fillet dry with a paper towel and trim the woody ends off the asparagus spears.
Brush half of the lemon-herb mixture over the salmon fillet and toss the remaining half with the asparagus spears until evenly coated.
Place the salmon on the grill, skin-side down, and cook for 4 to 5 minutes. Carefully flip and cook for another 3 to 4 minutes until the internal temperature reaches 145°F.
While the salmon cooks, place the asparagus on the grill and cook for 5 to 6 minutes, turning occasionally until tender and slightly charred.
Remove from heat and serve the salmon immediately alongside the grilled asparagus.