Preheat your grill or a heavy grill pan over medium-high heat until hot.
In a small mixing bowl, whisk together the olive oil, lemon juice, lemon zest, minced garlic, and dried oregano to create a marinade.
Place the salmon fillet on a plate and brush both sides with half of the lemon-herb mixture, then season with sea salt and black pepper.
In a separate bowl, toss the trimmed asparagus spears and cherry tomatoes with the remaining marinade until evenly coated.
Place the salmon on the grill, skin-side down, and cook for approximately 4-5 minutes without moving it to ensure a good sear.
Arrange the asparagus and tomatoes on the grill alongside the salmon, cooking them for 5-6 minutes while turning occasionally.
Carefully flip the salmon fillet and continue grilling for another 3 minutes, or until the fish is opaque and flakes easily with a fork.
Remove the salmon and charred vegetables from the grill and serve immediately while hot.