01 - Set oven temperature to 425°F and prepare a large rimmed baking sheet by lining it with parchment paper or foil.
02 - In a small bowl, combine olive oil, lemon juice, lemon zest, minced garlic, oregano, thyme, ½ teaspoon salt, and ¼ teaspoon black pepper; whisk until blended.
03 - Arrange green beans and sliced red onion on the baking sheet. Drizzle with half of the marinade and toss to coat evenly. Spread in a single layer, leaving space in the center for the salmon.
04 - Place salmon fillets in the center of the baking sheet. Brush each fillet with remaining marinade and sprinkle with the remaining salt and black pepper.
05 - Cook in the oven for 16 to 18 minutes until the salmon flakes easily and green beans are tender-crisp.
06 - Remove sheet from oven. Garnish with lemon wedges and chopped parsley if desired. Serve immediately.