Preheat your grill or grill pan to medium-high heat.
In a small bowl, whisk together the olive oil, minced garlic, dried oregano, sea salt, black pepper, lemon juice, and lemon zest to create the marinade.
Trim the woody ends off the asparagus and place them on a tray alongside the salmon fillet.
Brush the marinade generously over both the salmon and the asparagus spears, ensuring even coating.
Place the salmon on the grill, skin-side down if applicable, and cook for about 4-5 minutes per side until the fish is opaque and flakes easily with a fork.
Add the asparagus to the grill during the last 4-5 minutes of cooking, turning occasionally until they are tender and have light char marks.
Remove from the heat and serve immediately, garnished with an extra squeeze of fresh lemon if desired.