1. Pat the fish dry with paper towels. Drizzle olive oil over the fish, coating both sides and the insides. Sprinkle the fish all over with juice from one lemon; slice the second lemon into rounds. Season with salt and pepper, then stuff each sea bream cavity with half of the garlic, 2 oregano sprigs, and 2 lemon slices. Repeat for the second fish.
    
2. Spread onion rings and cherry tomatoes evenly onto a baking tray. Sprinkle with salt and pepper. Add olives, capers, and the remaining oregano sprigs. Drizzle the remaining olive oil on top. Place the two fish on the tray, facing each other, on top of the vegetables, and carefully pour the wine into a corner of the baking dish.
    
3. Bake in a preheated oven at 200°C (392°F) for about 40 minutes. Do not flip the fish during baking.

This is a perfect, healthy dish to celebrate March 25th, traditionally a day for eating fish.