1. Preheat your oven to 400 F (200 C). Line a large baking sheet with parchment paper for easy cleanup. This step is crucial for even cooking and preventing sticking.

2. In a small bowl, whisk together 1 tablespoon of olive oil, minced garlic, lemon juice, oregano, thyme, salt, and pepper. Place the salmon fillets on one side of the prepared baking sheet. Spoon about half of the lemon-garlic mixture over the salmon, ensuring each fillet is well coated.

3. In a large bowl, combine the broccoli florets, sliced red bell pepper, cherry tomatoes, and sliced red onion. Drizzle with the remaining 1 tablespoon of olive oil and the rest of the lemon-garlic mixture. Toss gently until all the vegetables are evenly coated.

4. Spread the seasoned vegetables in a single layer on the other side of the baking sheet, next to the salmon. Arrange the lemon slices over the salmon fillets. This helps infuse the fish with even more bright lemon flavor.

5. Transfer the baking sheet to the preheated oven and roast for 15-20 minutes, or until the salmon is cooked through and flakes easily with a fork, and the vegetables are tender-crisp. The exact cooking time will depend on the thickness of your salmon fillets.

6. Carefully remove the baking sheet from the oven. Divide the salmon and roasted vegetables among serving bowls. If desired, garnish with fresh chopped parsley for a pop of color and freshness. Serve immediately, perhaps over a bed of cooked quinoa or brown rice if you like.