Cut a lid from loaf of bread and scoop out bread from inside, so that an approximately 2 cm (approximately 1 inch) thick wall.
Peel cucumber and cut into thin slices. Rinse bell pepper, cut in half, remove seeds and ribs and cut into narrow strips. Drain tuna and dissect into small pieces. Peel onion, halve and cut into thin slices. Rinse tomatoes and cut into wedges. Peel eggs and cut into wedges.
In a bowl, mix cucumber, bell pepper, tomatoes, basil leaves, onion and olives with 4-5 tablespoons olive oil and 2-3 tablespoons wine vinegar, mix and season with salt and pepper mix. Then stir in tuna and season again with salt and pepper. Place salad in hollowed bread loaf, cover with egg slices and season with salt and pepper. Serve garnished with basil.