Preheat your grill or grill pan to medium-high heat.
In a small bowl, whisk together 0.25 tbsp of the olive oil, lemon juice, lemon zest, dill, parsley, and half of the sea salt and black pepper.
Brush the salmon fillet generously with the herb marinade on both sides.
In a separate bowl, toss the asparagus spears with the remaining 0.25 tbsp olive oil, garlic powder, and the remaining salt and pepper.
Place the salmon on the grill, skin-side down, and cook for 4-5 minutes.
Add the asparagus spears to the grill alongside the salmon.
Flip the salmon and cook for another 3-4 minutes until the fish is opaque and flaky, while turning the asparagus occasionally until tender-crisp.
Remove from the heat and serve the salmon and asparagus immediately while hot.