Prepare the fish. Scale and gut the sea bream. Rinse well under running water. Make a lengthwise incision with a knife right in the center where the main bone is located, on both sides.
Place the fish on a piece of parchment paper.
Season with salt (kosher or coarse sea salt) inside the belly and in the incisions.
Drizzle with 2 tablespoons of olive oil and 1 tablespoon of lemon juice.
Sprinkle 1 teaspoon of dried oregano. Then season the skin with some more salt and some pepper.
Close the parchment paper envelope-like and secure the top and bottom ends by folding and wrapping the edges tightly.
Take a big piece of aluminum foil, place the wrapped fish on top, and then wrap it with the foil. Again, closing the ends well.
Place the fish in a baking dish or pan that fits it. Pour some water into the pan to coat the bottom. This helps keep the fish moist and the skin from sticking to the bottom. Make sure there's a splash of water in the pan throughout baking.
Bake for 50 minutes. Unwrap partly to reveal the fish and give it a final roast for 5 to 7 minutes in the mid-top rack of the oven. Don't place it too close to the heat element, or the parchment paper may burn.
Carefully remove the fish with a spatula and transfer to a serving plate. Drain the fish and olive oil juices into a jug.
Mix 2 tablespoons of olive oil and one tablespoon of lemon juice into the fish juices. Then pour over the fish.
Serve with the remaining ½ teaspoon of dried oregano and fresh lemon on the side.
Notes
The calories are mainly from the olive oil used in this recipe. One tablespoon of olive oil is 119 kcal. So, unless you eat all the olive oil mixed with the fish juices, it's unlikely you'll get all the kcal mentioned above.