Preheat your oven to 190°C (375°F).
Lightly drizzle olive oil on a baking tray and place the cod fillets onto it. Season with black pepper and any optional salt.
Bake the cod for 10 minutes or until cooked through and flaking easily with a fork.
While the cod is baking, combine the chopped romaine, diced bell peppers, and sliced mushrooms in a large mixing bowl.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, oregano, and basil to create the dressing.
Pour the dressing over the salad ingredients and toss gently to coat everything evenly.
Once the cod is done, flake it slightly and arrange it on top of the salad.
Garnish with fresh mint leaves and serve with lemon wedges on the side for an extra zesty touch.