Cruditè of croaker with caper fruits

Clean and fillet the croaker, obtaining 2 fillets. Arrange the ice cream in a baking dish and pour in the lemon and orange juice, then add the pepper and leave everything in the fridge to marinate for at least 2 hours. Meanwhile, slice the half onion into thin slices. Carefully wash the lettuce leaves and if necessary cut them slightly, wash and cut the tomatoes in two. Arrange a lettuce leaf, a marinated croaker fillet, onions and cherry tomatoes on the plate. Then add the caper fruits before serving.