Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Slice the red bell pepper into thin strips and break the broccoli into bite-sized florets.
In a large bowl, toss the broccoli and bell pepper with 0.5 tablespoons of olive oil, 0.125 teaspoons of sea salt, and 0.125 teaspoons of black pepper.
Spread the vegetables in a single layer on the prepared sheet pan and roast for 10 minutes to begin softening.
While the vegetables roast, mince the garlic and finely chop the fresh parsley.
Pat the cod fillets dry with a paper towel and season both sides with the remaining olive oil, garlic, parsley, dried oregano, and the rest of the salt and pepper.
Remove the pan from the oven, push the vegetables to the sides, and place the cod fillets in the center.
Squeeze the juice of the half lemon over the fish and vegetables.
Return the pan to the oven and bake for an additional 12 to 15 minutes until the cod is opaque and flakes easily with a fork.
Serve the roasted cod and vegetables over the warm cooked quinoa to soak up the bright citrus juices.