Preheat your oven to 425°F and line a large sheet pan with parchment paper. Arrange bell peppers, red onion, cherry tomatoes, and olives across the pan in a single layer for even roasting.

Drizzle vegetables with 2 tablespoons olive oil, then scatter minced garlic throughout. Toss gently to coat, then season with half the oregano and a pinch of salt and pepper. Roast for 8 minutes until vegetables begin softening.

Remove the pan from the oven and create space in the center for seafood fillets. Pat your beautiful Mediterranean fish dry with paper towels—this ensures proper searing and moisture retention during cooking.

Arrange seafood fillets on top of the vegetables, then drizzle with remaining 1 tablespoon olive oil and fresh lemon juice. Season with remaining oregano, sea salt, and black pepper. Scatter capers and lemon slices over everything. Return to oven for 12 minutes until the fish flakes easily with a fork.

During the final 2 minutes of cooking, the sheet pan Mediterranean seafood recipe reaches perfection when vegetables caramelize slightly at edges. Watch carefully to prevent overcooking—the residual heat continues cooking even after removal.

Remove from oven and immediately garnish with fresh parsley and basil for bright, herbaceous finishing touches. The vibrant colors and aromatic herbs announce elegance before the first bite.