Preheat your grill or a heavy grill pan over medium-high heat to ensure a good sear.
Pat the salmon fillet completely dry with a paper towel to help the crust form.
In a small glass bowl, whisk together the olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Brush the herb marinade generously over the flesh side of the salmon fillet.
Trim the woody ends off the asparagus and toss the spears with melted ghee and a pinch of salt.
Place the salmon on the hot grill, skin-side down first, and cook undisturbed for 4 to 5 minutes.
Carefully flip the salmon using a wide spatula and grill for another 3 to 4 minutes until the internal temperature reaches 145 degrees Fahrenheit.
Add the asparagus to the grill alongside the salmon during the last 5 minutes of cooking, turning occasionally until tender and lightly charred.
Remove from heat and let the salmon rest for 2 minutes before serving with the grilled asparagus and an extra squeeze of fresh lemon.