Preheat your grill or a heavy grill pan over medium-high heat until hot.
In a small bowl, whisk together 1 teaspoon of olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Brush the salmon fillet generously with the lemon-herb marinade and let it rest for 5 minutes at room temperature.
Trim the woody ends off the asparagus and toss the spears with the remaining 1 teaspoon of olive oil and a tiny pinch of salt.
Place the salmon on the grill, skin-side down, and cook undisturbed for 4 to 5 minutes.
Add the asparagus to the grill alongside the salmon and cook, turning the spears occasionally, for about 5 minutes.
Carefully flip the salmon and grill for an additional 2 to 3 minutes until the flesh is opaque and flakes easily with a fork.
Remove the salmon and charred asparagus from the heat and serve immediately while hot.