Preheat your grill or grill pan to medium-high heat.
In a small bowl, whisk together half of the olive oil, the lemon juice, lemon zest, dill, parsley, and half of the sea salt and black pepper.
Brush the herb marinade evenly over the salmon fillet.
In a separate bowl, toss the asparagus spears with the remaining olive oil, garlic powder, and the rest of the salt and pepper.
Place the salmon on the grill, skin-side down, and cook for about 4 to 5 minutes.
Carefully flip the salmon and grill for another 3 to 4 minutes until the internal temperature reaches 145 degrees Fahrenheit.
While the salmon cooks, place the asparagus on the grill and cook for 5 to 6 minutes, turning occasionally until slightly charred and tender.
Remove from heat and serve the salmon immediately with the grilled asparagus.