Begin by preparing the ingredients. Wash the green beans and trim the ends. Halve the cherry tomatoes with a sharp knife and drain the canned tuna in water thoroughly in a colander. Have the eight black olives and four anchovy fillets ready.
Bring a pot of water to a boil for the two eggs and hard-boil them for eight minutes. Simultaneously bring a second pot of water to a boil and cook the green beans until tender-crisp, about six minutes. Drain the eggs, shock them in cold water and peel. Drain the green beans and rinse briefly with cold water to stop the cooking process.
Take a large serving platter to assemble the dish. Arrange the cooled green beans over the bottom. Flake the drained tuna with a fork into large chunks and distribute it along with the halved cherry tomatoes over the platter. Quarter the peeled eggs and arrange them on top. Distribute the olives and anchovy fillets over everything.
Drizzle the lemon dressing evenly over the assembled salad so all ingredients are lightly coated. Tear the fresh basil into pieces and scatter it over the dish as a final touch. Serve immediately.