01 - Preheat oven to 400°F. Line a large sheet pan with parchment paper or lightly grease with cooking spray.
02 - In a small bowl, whisk together olive oil, lemon juice, minced garlic, dried oregano, salt, black pepper, and lemon zest until well combined.
03 - Arrange asparagus, cherry tomatoes, and red onion wedges on the prepared sheet pan. Drizzle with half the marinade and toss to coat evenly. Spread vegetables in a single layer, leaving space for salmon fillets.
04 - Place salmon fillets on the pan, skin-side down if applicable. Brush the tops generously with remaining marinade, ensuring each fillet is well coated.
05 - Roast in preheated oven for 16-20 minutes, or until salmon flakes easily with a fork and vegetables are tender-crisp.
06 - Remove from oven. Sprinkle with chopped fresh parsley and arrange lemon wedges around the pan. Serve immediately while hot.