Preheat your oven to 425°F (220°C).
Slice the broccoli into florets, the red bell pepper into strips, and the red onion into wedges.
In a small bowl, whisk together olive oil, juice from half a lemon, and the minced garlic.
Place the chicken breast and salmon fillet on one side of a large sheet pan. On the other side, arrange the broccoli, red bell pepper, and red onion.
Drizzle the lemon-garlic olive oil mixture evenly over the chicken, salmon, and vegetables. Gently toss the vegetables to coat.
Season the chicken, salmon, and vegetables with salt and pepper to taste.
Roast in the preheated oven for 15-18 minutes, or until the chicken is cooked through and the salmon is just flaky. The vegetables should be tender and lightly charred.
Remove from the oven and serve immediately, enjoying the perfect balance of crispy chicken, flaky salmon, and zesty roasted vegetables.