Preheat your grill or grill pan to medium-high heat.
In a small bowl, whisk together the olive oil, lemon zest, lemon juice, garlic powder, and dried oregano to create the marinade.
Season the salmon fillet and asparagus spears evenly with sea salt and black pepper.
Brush the lemon-herb mixture over both sides of the salmon and the asparagus spears.
Place the salmon on the grill, skin-side down, and cook for 4-5 minutes without moving it to ensure a good sear.
Place the asparagus on the grill alongside the salmon, turning occasionally to achieve light char marks.
Flip the salmon carefully and cook for an additional 3-4 minutes until the internal temperature reaches 145°F and the asparagus is tender.
Remove from heat and let the salmon rest for 2 minutes before serving to lock in the moisture.