01 - Preheat oven to 400°F. Line a large baking tray with parchment paper.
02 - Rinse sea bream under cold water and pat dry with paper towels. Score each fish 2 to 3 times on both sides.
03 - Rub each fish inside and out with 1 tablespoon olive oil. Season generously with salt and freshly ground black pepper.
04 - Fill cavities with half of the lemon slices, garlic, thyme, parsley, and rosemary sprigs.
05 - Place remaining lemon slices, red onion, and cherry tomatoes on the baking tray. Position the stuffed fish on top.
06 - Scatter leftover herbs and garlic evenly over the fish and vegetables.
07 - Bake for 22 to 25 minutes until fish is opaque, flakes easily, and remains moist.
08 - Serve hot, drizzled with pan juices and garnished with fresh herbs.