Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Slice the red bell pepper into bite-sized strips and trim the broccoli into uniform florets.
Place the broccoli and bell peppers on one side of the sheet pan, tossing them with half of the olive oil, a pinch of sea salt, and black pepper.
Place the cod fillets on the other side of the sheet pan.
In a small bowl, whisk together the remaining olive oil, lemon juice, dried oregano, and garlic powder.
Brush the lemon-herb mixture evenly over the top of the cod fillets, seasoning with the remaining salt and pepper.
Bake for 12 to 15 minutes, or until the vegetables are tender-crisp and the cod is opaque and flakes easily with a fork.
While the fish bakes, gently warm the pre-cooked quinoa in a small saucepan or microwave.
Plate the baked cod and roasted vegetables over the bed of warm quinoa and serve immediately.