Toast slices of bread in a toaster. Drain tuna in a sieve. Wash parsley, dab dry, remove leaves and chop finely. Mix ricotta, parsley, oil and lemon juice.
Season to taste with salt and pepper. Wash and clean the tomatoes and cut them into 8 slices. Clean, wash and drain the lettuce in a sieve. Cut caper apples in half. Spread slices of bread with ricotta, cover with slices of tomato.
Grate the cheese and sprinkle on the crêpes. Bake in the preheated oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3) for approx. 15 minutes. Wash the chives, shake dry, cut into fine rolls and sprinkle on top.