Prepare the fish: Preheat the oven to 190°C (375°F). Pat the gilt bream dry and make a few shallow cuts on each side.
Season: Place the fish in a baking dish. Drizzle with olive oil, then season inside and out with salt and black pepper.
Stuff and arrange: Insert garlic slices, lemon slices, and herbs into the cavity of each fish. Add remaining lemon slices around the fish.
Bake: Bake uncovered for 22–25 minutes, until the flesh is opaque and flakes easily with a fork.
Rest and serve: Let the fish rest for 5 minutes before serving. Spoon the pan juices over the top.